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Physics  Unit  P2  ‘Physics  for  Your  Future’  

Study  and  Revision  Pack  (Higher  Paper)    

Content   Page  number  P2  overview  and  assessment  tracking  

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Formulae  sheet   3  P2.1  Specification  statements   4  P2.1  Exam  Questions     5  P2.2  Specification  statements   16  P2.2  Exam  Questions     17  P2.3  Specification  statements   25  P2.3  Exam  Questions     27  P2.4  Specification  statements   34  P2.4  Exam  Questions     36  P2.5  Specification  statements   43  P2.5  Exam  Questions     44  P2.6  Specification  statements   53  P2.6  Exam  Questions     54  

   Revision  tips  in  appendix   62  

 

 

 

Name:   __________________________________  

Form:   __________________________________  

     

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Overview  and  assessment  tracking  Please  use  the  table  below  to  keep  track  of  your  revision.  The  smarter  you  work  the  better  results.  

  Revision  complete?  

Questions  completed?  

Marks  in  first  try  

%  in  first  try  

Marks  in  second  try  

%  in  second  try  

 P2.1                P2.2              P2.3              P2.4              P2.5              P2.6              

 

Use  the  grade  boundaries  below  as  a  guide  to  the  grade  you  are  achieving:  

 

 

 

 

 

 

%   Grade  90   A*  80   A  70   B  60   C  50   D  <50   U  

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P2.1  Specification  statements  To

pic   P2  Specification  Physics  for  your  future   RAG  

Curren

t   Revised  !  

1   2   3  

Topic  1:  Static

 and

 Current  Electric

ity  

1.1  Be  able  to  describe  the  structure  of  the  atom,  limited  to  the  position,  mass  and  charge  of  protons,  neutrons  and  electrons    

       

1.2  Be  able  to  explain  how  an  insulator  can  be  charged  by  friction,  through  the  transfer  of  electrons.    

       

1.3  Be  able  to  explain  how  the  material  gaining  electrons  becomes  negatively  charged  and  the  material  losing  electrons  is  left  with  an  equal  positive  charge.    

       

1.4  Know  that  like  charges  repel  and  unlike  charges  attract.            

1.5  Be  able  to  demonstrate  an  understanding  of  common  electrostatic  phenomena  in  terms  of  movement  of  electrons,  including:    

       

a) shocks  from  everyday  objects            b) lightning            c) attraction  by  induction  such  as  a  charged  balloon  

attracted  to  a  wall  and  a  charged  comb  picking  up  small  pieces  of  paper    

       

1.6  Be  able  to  explain  how  earthing  removes  excess  charge  by  movement  of  electrons.    

       

1.7  Be  able  to  explain  some  of  the  uses  of  electrostatic  charges  in  everyday  situations,  including  paint  and  insecticide  sprayers.    

       

1.8  Be  able  to  demonstrate  an  understanding  of  some  of  the  dangers  of  electrostatic  charges  in  everyday  situations,  including  fuelling  aircraft  and  tankers  together  with  the  use  of  earthing  to  prevent  the  build-­‐up  of  charge  and  danger  arising.    

       

1.9  Know  that  an  electric  current  is  the  rate  of  flow  of  charge.            1.10  Know  that  the  current  in  metals  is  a  flow  of  electrons.            1.11  Be  able  to  use  the  equation:    charge  (coulomb,  C)  =  current  (ampere,  A)  x  time  (second,  s)  Q  =  I  x  t  

       

1.12  Know  that  cells  and  batteries  supply  direct  current  (d.c.).            1.13  Be  able  to  demonstrate  an  understanding  that  direct  current  (d.c.)  is  movement  of  charge  in  one  direction  only.    

       

   

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P2.1  Exam  Questions-­‐  58  marks,  58  minutes.  

Q1. (a) A lightning strike on a metal tower can be described as follows.

In the cloud. A thunder cloud contains moving ice particles. Some of these ice particles are negatively charged and some are positively charged. The negatively charged particles move to the bottom of the cloud.

When the charged cloud is over the metal tower. A charge builds up on the top of the metal tower as the cloud passes over. During the lightning flash. Eventually a flash of lightning travels between the cloud and the tower.

(i) Which row of this table is correct when the cloud is over the top of the tower before the lightning flash? Put a cross ( ) in the box next to your answer.

(1)

charge on top of the cloud is

charge on top of the tower is

A negative negative B negative positive C positive positive D positive negative

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(ii) Here are four statements. Three of these are a reason for what happens at each stage.

Choose the best reason for each of the stages listed below by writing its number in the box next to the description of what happens. One has been done for you. A reason can only be used once.

(2)

(iii) Explain what happens to the charge on the metal tower as a result of the lightning flash.

(2) ..............................................................................................................................................

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.............................................................................................................................................. (b) During the lightning flash a total charge of 52 C flows. The average current is 2600 A. Calculate the duration of the flash in seconds.

(3)

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(c) When fuel tanks on an aircraft are being filled, the aircraft, fuel pipes and tanker are connected by a metal wire to the ground.

Explain why this greatly reduces the chance of a spark.

(2) ..............................................................................................................................................

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(Total for Question is 10 marks) Q2. (a) A student wins a trophy. It is a metal cup on a black plastic base.

The student cleans the trophy. She holds one of the metal handles and rubs the rest of the trophy with a dry cloth. (i) Complete the sentence by putting a cross ( ) in the box next to your answer.

The plastic base becomes negatively charged because it gains (1)

A atoms B becquerel C einstein D radium

(ii) Explain why the base gains a negative charge when she rubs the trophy with the cloth.

(2) ..............................................................................................................................................

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(iii) The metal cup does not become charged when she rubs the trophy. Suggest why the cup does not become charged.

(2) ..............................................................................................................................................

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.............................................................................................................................................. (iv) Some dust particles in the air drift near to the plastic base just after she cleans the trophy.

Which diagram shows the correct distribution of charges on a dust particle near to the charged plastic base? Put a cross ( ) in the box next to your answer.

(1)

(b) Describe one situation where separation of electric charge can create a spark.

(2) ..............................................................................................................................................

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(Total for Question = 8 marks)

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Q3. Using static electricity Waste gases contain smoke particles. The diagram shows how smoke particles can be removed from waste gases as they rise through a chimney.

(a) Complete the sentence by putting a cross ( ) in the box next to your answer. When the smoke particles go through the metal grid they become negatively charged. This is because they

(1) A gain electrons B gain protons C lose electrons D lose protons

(b) When the negatively charged smoke particles move up the chimney, they are attracted to the metal plates.

(i) State why the metal plates attract the smoke particles.

(1) ..............................................................................................................................................

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(ii) State what happens to the charge on the smoke particles when they reach the metal plate.

(1) ..............................................................................................................................................

(c) There is a current of 1.4 A between the grid and the plates.

(i) Calculate the charge transferred by this current in two minutes. State the unit.

(3)

charge = ........................................ unit ........................................ (ii) The potential difference between the grid and the plate is 400 V. Calculate the electrical energy transferred in two minutes.

(2)

energy transferred = ....................................... joules

(Total for Question = 8 marks) Q4. A battery sends a current through a metal wire. (a) (i) Complete the sentence by putting a cross ( ) in the box next to your answer.

Direct current is movement of charge

(1) A backwards and forwards B in many directions C in one direction D up and down

(ii) Complete the sentence by putting a cross ( ) in the box next to your answer.

The particles that flow in the metal wire are

(1) A atoms B electrons C protons D neutrons

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(b) The current in a wire is 3.7 A. Calculate the charge that flows into the wire in 13 s.

(2)

.............................................................................................................................................. (c) Plastic is an insulator. A student rubs a piece of plastic with a cloth. This gives the plastic a negative charge. (i) Explain how the plastic is charged by the rubbing.

(2) ..............................................................................................................................................

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.............................................................................................................................................. (ii) The cloth is also charged when it rubs against the plastic. Describe the charge on the cloth.

(2) ..............................................................................................................................................

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(Total for Question is 8 marks)

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Q5. Electrostatic discharge (a) Marie works in an office which has a nylon carpet. She walks across the carpet towards her filing cabinet. There is friction between her shoes and the carpet. When she touches the metal handle of her filing cabinet she feels an electric shock.

(i) State the name of the charged particles which have been transferred between the carpet and her shoes.

(1) ..............................................................................................................................................

(ii) The following sentences explain how Marie got the electric shock. The sentences are in the wrong order. Put them in the correct order by numbering the boxes. Two have been done for you.

(2)

actions order in which the actions happen

Marie walks across the nylon carpet 1 charge flows from Marie to the filing cabinet

Marie touches the handle 4 charge is transferred by friction on to Marie

Marie has lost her negative charge a negative charge builds up on Marie

(b) Marie has another filing cabinet which has a black conductive strip at the top. This black strip helps to prevent electric shocks. This strip has a high resistance but still conducts charge.

If Marie touches the strip before touching the handle she does not feel a shock. Explain, using the idea of electric current, why Marie does not feel a shock.

(3) ..............................................................................................................................................

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*(c) Sparks from electrostatic discharge can sometimes be very dangerous. They can cause a fire or an explosion. Safety precautions are taken to reduce risks. Explain how safety precautions, in a particular situation, reduce the risks of fire or explosion. You may draw a labelled diagram to help with your answer.

(6)

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(Total for Question = 12 marks)

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Q6. (a) Vicky combs her hair with a plastic hair comb. The comb now has a negative charge. (i) Complete the sentence by putting a cross ( ) in the box next to your answer. The comb has a negative charge because it has

(1) A gained electrons B lost electrons C gained protons D lost protons

(ii) Vicky's hair has also become charged. Explain how Vicky's hair has become charged.

(2) ..............................................................................................................................................

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.............................................................................................................................................. (iii) Vicky holds the comb over a small piece of metal foil. The foil jumps up and sticks to the comb.

Show on the diagram where the foil is negatively charged.

(1) (b) Vicky combs her hair with a metal comb. Then she tries to pick up some small pieces of metal foil with the comb. The metal comb does not pick up any pieces of metal foil.

Explain why the metal foil is not picked up by the comb.

(2) ..............................................................................................................................................

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(c) The picture shows an electrostatic paint sprayer about to be used to paint a metal object.

When the paint particles leave the sprayer, they are negatively charged. Explain the benefits of using this sprayer compared with one that does not charge the paint.

(6) ..............................................................................................................................................

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(Total for Question is 12 marks)

 

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P2.2  Specification  statements  To

pic   P2  Specification  Physics  for  your  future   RAG  

Curren

t   Revised  !  

1   2   3  

Topic  2:  Con

trollin

g  an

d  using  electric  current  

2.1  Be  able  to  describe  how  an  ammeter  is  placed  in  series  with  a  component  to  measure  the  current,  in  amps,  in  the  component.    

       

2.2  Be  able  to  explain  how  current  is  conserved  at  a  junction.            

2.3  Be  able  to  explain  how  the  current  in  a  circuit  depends  on  the  potential  difference  of  the  source.    

       

2.4  Be  able  to  describe  how  a  voltmeter  is  placed  in  parallel  with  a  component  to  measure  the  potential  difference  (voltage),  in  volts,  across  it.    

       

2.5  HT  only:  Be  able  to  demonstrate  an  understanding  that  potential  difference  (voltage)  is  the  energy  transferred  per  unit  charge  passed  and  hence  that  the  volt  is  a  joule  per  coulomb.    

       

2.6  Revise  any  investigations  on  the  relationship  between  potential  difference  (voltage),  current  and  resistance.    

       

2.7  Be  able  to  explain  how  changing  the  resistance  in  a  circuit  changes  the  current  and  how  this  can  be  achieved  using  a  variable  resistor    

       

2.8  Be  able  to  use  the  equation:    potential  difference  (volt,  V)  =  current  (ampere,  A)  x  resistance  (ohm,  Ω)  V  =  I  x  R  

       

2.9  Be  able  to  demonstrate  an  understanding  of  how  current  varies  with  potential  difference  for  the  following  devices    

       

a)  filament  lamps            b)  diodes            

c)  fixed  resistors            

2.10  Be  able  to  demonstrate  an  understanding  of  how  the  resistance  of  a  light-­‐  dependent  resistor  (LDR)  changes  with  light  intensity    

       

2.11  Be  able  to  demonstrate  an  understanding  of  how  the  resistance  of  a  thermistor  changes  with  change  of  temperature  (negative  temperature  coefficient  thermistors  only)    

       

2.12  Be  able  to  explain  why,  when  there  is  an  electric  current  in  a  resistor,  there  is  an  energy  transfer  which  heats  the  resistor    

       

2.13  HT  only:  Be  able  to  explain  the  energy  transfer  (in  2.12  above)  as  the  result  of  collisions  between  electrons  and  the  ions  in  the  lattice    

       

2.14  Be  able  to  distinguish  between  the  advantages  and  disadvantages  of  the  heating  effect  of  an  electric  current    

       

2.15  Be  able  to  use  the  equation  [appropriate  units  in  ()]:            

 

   

17  

P2.2  Exam  Questions-­‐  40  marks,  40  minutes  

Q7. (a) The diagram shows an electric circuit with two resistors, R and S.

(i) R has a resistance of 11 ohms.

Calculate the potential difference across R. (2)

.............................................................................................................................................. (ii) Use information from the diagram to calculate the current in S.

(1)

.............................................................................................................................................. (iii) Complete the sentence by putting a cross ( ) in the box next to your answer. A student wants to measure the battery voltage with a voltmeter. The voltmeter should be placed

(1) A in series with the battery B in parallel with the battery C in parallel with the ammeter D in series with either resistor R or S (b) Explain why the temperature of a resistor increases when a current passes through it.

(2) ..............................................................................................................................................

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*(c) A resistor is a circuit component. Two other circuit components are a light dependent resistor (LDR) and a thermistor. Explain how LDRs and thermistors can be used to control the current in a circuit.

(6)

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(Total for Question is 12 marks)

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Q8. (a) A designer is going to use a thermistor in a temperature gauge. He connects the thermistor into this circuit.

He heats the thermistor and measures the current at different temperatures. Here are some of the results plotted on a graph.

At 47 °C the current was 0.138 A. (i) Plot this value on the graph.

(1) (ii) Draw the curve of best fit through the points.

(1)

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(iii) The supply voltage is 12 V. At 20 °C the current is 0.047 A.

Calculate the resistance of the thermistor at this temperature. (3)

.............................................................................................................................................. (iv) Use this graph of current against temperature to explain the relationship between resistance and temperature for this thermistor.

(2) ..............................................................................................................................................

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.............................................................................................................................................. (b) (i) When there is an electric current in a resistor, the resistor gets hot. Explain why the resistor gets hot.

(2) ..............................................................................................................................................

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.............................................................................................................................................. (ii) Suggest why the thermistor in a temperature gauge might indicate a temperature slightly higher than the actual temperature of its surroundings.

(1) ..............................................................................................................................................

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(Total for Question = 10 marks)

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Q9.

(a) Some students investigate the electrical resistance of different components using this circuit.

(i) Which row of the table is correct for both meters P and Q? Put a cross ( ) in the box next to your answer.

(1) meter P is meter Q is

A an ammeter an ammeter B an ammeter a voltmeter C a voltmeter a voltmeter D a voltmeter an ammeter

(ii) One of the components being investigated is a 12 ohm resistor. When it is in the circuit, the ammeter reading is 0.50 A. Calculate the voltmeter reading.

(2)

.............................................................................................................................................. (iii) The students reduce the resistance of the variable resistor. State what happens to the readings on each of the meters P and Q.

(2) ..............................................................................................................................................

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(iv) The students then reduce the voltage of the power supply. State what happens to the current in the circuit.

(1) ..............................................................................................................................................

(b) The graphs L, M and N each show how the current in a component varies with the potential difference (voltage) across that component.

Match each graph with the symbol of the component to which it applies. Draw lines to connect each symbol with its correct graph.

(Total for Question is 8 marks)

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Q10. Using electric current (a) The photograph shows a device used to measure the amount of light.

The circuit diagram shows how the components inside this device are connected.

(i) Complete the sentence by putting a cross ( ) in the box next to your answer. The meter used in this circuit is

(1) A a voltmeter connected in series with the LDR B a voltmeter connected in parallel with the LDR C an ammeter connected in series with the LDR D an ammeter connected in parallel with the LDR (ii) The amount of light entering the light-dependent resistor (LDR) increases. Which row of the table correctly describes the change in the resistance of the LDR and the change in the current in the circuit? Put a cross ( ) in the box next to your answer.

(1)

resistance of the LDR current in circuit

A increases decreases B increases increases C decreases decreases D decreases increases

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(iii) The device is used as a light meter. It has a 9 V battery. Calculate the current when the resistance of the LDR is 600Ω.

(3)

current = ........................................ A (iv) When the light meter has been used for a long time, the meter reading becomes incorrect. Suggest what has happened.

(2) ..............................................................................................................................................

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.............................................................................................................................................. (b) A different light meter has a diode in its circuit.

(i) Explain what happens when the battery is reversed.

(2) ..............................................................................................................................................

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.............................................................................................................................................. (ii) Suggest why the manufacturer of the light meter has included a diode.

(1) ..............................................................................................................................................

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(Total for Question is 10 marks)    

25  

P2.3  Specification  statements    Top

ic  

P2  Specification  Physics  for  your  future   RAG  

Curren

t   Revised  !  

1   2   3  

Topic  3:  M

otion  an

d  Forces  

3.1  Be  able  to  demonstrate  an  understanding  of  the  following  as  vector  quantities:    

       

a)  displacement            b)  velocity            c)  acceleration            d)  force            3.2  Be  able  to  interpret  distance/time  graphs  including  determination  of  speed  from  the  gradient.    

       

3.3  Know  that  velocity  is  speed  in  a  stated  direction            3.4  Be  able  to  use  the  equation:            speed  (m/s)  =  distance  (m)  /  time  (s)    s  =  d  /  t  

       

3.5  Be  able  to  use  the  equation:    acceleration  (metre  per  second  squared,  m/s2)  =  change  in  velocity  (metre  per  second,  m/s)  /  time  taken  (second,  s)  a  =  (v  -­‐  u)  /  t  

       

3.6  Be  able  to  interpret  velocity/time  graphs  to:            a)  compare  acceleration  from  gradients  qualitatively            b)  calculate  the  acceleration  from  the  gradient  (for  uniform  acceleration  only)    

       

c)  determine  the  distance  travelled  using  the  area  between  the  graph  line  and  the  time  axis  (for  uniform  acceleration  only    

       

3.7  Be  able  to  draw  and  interpret  a  free-­‐body  force  diagram            

3.8  Be  able  to  demonstrate  an  understanding  that  when  two  bodies  interact,  the  forces  they  exert  on  each  other  are  equal  in  size  and  opposite  in  direction  and  that  these  are  known  as  action  and  reaction  forces    

       

3.9  Be  able  to  calculate  a  resultant  force  using  a  range  of  forces  (limited  to  the  resultant  of  forces  acting  along  a  line)  including  resistive  forces    

       

3.10  Be  able  to  demonstrate  an  understanding  that  if  the  resultant  force  acting  on  a  body  is  zero,  it  will  remain  at  rest  or  continue  to  move  at  the  same  velocity    

       

3.11  Be  able  to  demonstrate  an  understanding  that  if  the  resultant  force  acting  on  a  body  is  not  zero,  it  will  accelerate  in  the  direction  of  the  resultant  force    

       

26  

3.12  Be  able  to  demonstrate  an  understanding  that  a  resultant  force  acting  on  an  object  produces  an  acceleration  which  depends  on:    

       

a)  the  size  of  the  resultant  force            b)  the  mass  of  the  object            3.13  Be  able  to  use  the  equation:    force  (newton,  N)  =  mass  (kilogram,  kg)  x  acceleration  (metre  per  second  squared,  m/s2)  F  =  m  x  a  

       

3.14  Be  able  to  use  the  equation:    weight  (newton,  N)  =  mass  (kilogram,  kg)  x  gravitational  field  strength  (newton  per  kilogram,  N/kg)  W  =  m  x  g  

       

3.15  Revise  any  investigations  on  the  relationship  between  force,  mass  and  acceleration    

       

3.16  Know  that  in  a  vacuum  all  falling  bodies  accelerate  at  the  same  rate    

       

3.17  Be  able  to  demonstrate  an  understanding  that:            

a)  when  an  object  falls  through  an  atmosphere  air  resistance  increases  with  increasing  speed    

       

b)  air  resistance  increases  until  it  is  equal  in  size  to  the  weight  of  the  falling  object    

       

c)  when  the  two  forces  are  balanced,  acceleration  is  zero  and  terminal  velocity  is  reached    

       

 

 

   

27  

P2.3  Exam  Questions-­‐  41  marks,  41  minutes.  

Q11.  (a) A car is travelling along a level road.

(i) Complete the sentence by putting a cross ( ) in the box next to your answer.

When the velocity of the car is constant, the force of friction on it is

(1) A zero B greater than the driving force C smaller than the driving force D the same size as the driving force

(ii) The car now accelerates in a straight line. Its average acceleration is 12 m/s2.

Calculate the increase in velocity of the car in 4.0 s.

(3)

.............................................................................................................................................. (b) This table shows data about two other cars.

The owner of the family car claims that although the sports car has greater acceleration, it produces a smaller accelerating force than his family car. Explain how these figures support his claim.

(2) ..............................................................................................................................................

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28  

*(c) After going to the shops, a car driver places a bag of shopping on the passenger seat. During the journey home, the driver has to use the brakes to stop very suddenly. The driver is wearing a seat belt.

Explain what happens next to the car, the driver and the shopping bag.

(6)

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(Total for Question = 12 marks)

29  

Q12.

A water tank drips water.

(a) Scientists could use four quantities to describe the movement of the water drops. Three of these quantities are vectors. The other quantity is a scalar.

acceleration force mass velocity

(i) Complete the sentence by putting a cross ( ) in the box next to your answer. The scalar quantity is

(1) A acceleration B force C mass D velocity (ii) Complete the following sentence using one of the quantities from the word box above.

(1) In a vacuum, all bodies falling towards the Earth's surface have the same . . . . . . . . . . . . . . . . . . . . . . . (b) The mass of one water drop is 0.000 08 kg. Calculate its weight. (gravitational field strength is 10 N/kg)

(2)

weight = . . . . . . . . . . . . . . . . . . . . . . N (c) The water drop falls to the ground, 13 m below, in 1.7 s. Calculate the average speed of the drop while it is falling.

(2)

average speed = . . . . . . . . . . . . . . . . . . . . . . m/s

30  

*(d) The tank is a long way above the ground. It drips at a steady rate. The first drawing shows water drops which have just left the tank. The second drawing shows water drops which are near to the ground.

Explain why the drops which are near to the ground are an equal distance apart but the drops which have just started to fall are not.

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(Total for Question is 12 marks)

31  

Q13. Forces and motion The graph shows a velocity-time graph for a cyclist over a time of 60 s.

(a) (i) When is the cyclist travelling with greatest velocity? Put a cross ( ) in the box next to your answer.

(1) A for the first 15 seconds B between 15 and 40 seconds C between 40 and 50 seconds D for the last 10 seconds (ii) Calculate how long the cyclist is stationary for.

(1)

answer = .................................... seconds (b) The cyclist in this picture is travelling at a constant velocity. Her muscles produce a driving force of 15 N.

Draw an arrow on the diagram to show the size and direction of the overall resistive force acting on the cyclist.

(1)

32  

(c) The cyclist accelerates at 1.4 m/s2. The mass of the cyclist and bicycle is 60 kg.

(i) Calculate the resultant force.

(2)

resultant force = ....................................... N (ii) The cyclist accelerates for 8 s. Calculate the increase in velocity during this time.

(3)

increase in velocity = ............................... m/s

(Total for Question is 8 marks)

33  

Q14. The graph shows how the velocity of a small car changes with time.

(a) Complete the sentence by putting a cross ( ) in the box next to your answer.

The resultant force on the car will be zero when the car is

(1) A accelerating B decelerating C changing velocity D moving at a constant velocity (b) (i) Use the graph to estimate the velocity of the car at three seconds.

(1) .............................................................................................................................................. (ii) Calculate the acceleration of the car when it is speeding up.

(2)

acceleration = . . . . . . . . . . . . . . . . . . . . . . m/s2 (iii) Explain why the units of acceleration are m/s2.

(2) ..............................................................................................................................................

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.............................................................................................................................................. (iv) Show that the car travels further at a constant velocity than it does when it is slowing down.

(3) ..............................................................................................................................................

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(Total for Question is 9 marks)

34  

P2.4  Specification  statements  To

pic   P2  Specification  Physics  for  your  future   RAG  

Curren

t   Revised  !  

1   2   3  

Topic  4:  M

omen

tum,  ene

rgy,  work  an

d  po

wer  

4.1  Know  that  the  stopping  distance  of  a  vehicle  is  made  up  of  the  sum  of  the  thinking  distance  and  the  braking  distance    

       

4.2  Be  able  to  demonstrate  an  understanding  of  the  factors  affecting  the  stopping  distance  of  a  vehicle,  including:    

       

a)  the  mass  of  the  vehicle            b)  the  speed  of  the  vehicle            

c)  the  driver’s  reaction  time            d)  the  state  of  the  vehicle’s  brakes            e)  the  state  of  the  road            f)  the  amount  of  friction  between  the  tyre  and  the  road  surface    

       

4.3  Revise  any  investigations  on  the  forces  required  to  slide  blocks  along  different  surfaces,  with  differing  amounts  of  friction    

       

4.4  Be  able  to  use  the  equation:    momentum  (kilogram  metre  per  second,  kg  m/s)  =  mass  (kilogram,  kg)  x  velocity  (metre  per  second,  m/s)  to  calculate  the  momentum  of  a  moving  object  momentum  =  mass  x  velocity  momentum  =  mv  

       

4.5  Be  able  to  demonstrate  an  understanding  of  momentum  as  a  vector  quantity    

       

4.6  Be  able  to  demonstrate  an  understanding  of  the  idea  of  linear  momentum  conservation    

       

4.7  Be  able  to  demonstrate  an  understanding  of  the  idea  of  rate  of  change  of  momentum  to  explain  protective  features  including  bubble  wraps,  seat  belts,  crumple  zones  and  air  bags    

       

4.8  Revise  any  investigations  on  how  crumple  zones  can  be  used  to  reduce  the  forces  in  collisions    

       

4.9  HT  only:  Be  able  to  use  the  equation:    force  (newton,  N)  =  change  in  momentum  (kilogram  metre  per  second,  kg  m/s)  /  time  (second,  s)  F  =  (mv  -­‐  mu)  /  t  to  calculate  the  change  in  momentum  of  a  system,  as  in  4.6  

       

4.10  Be  able  to  use  the  equation:  work  done  (joule,  J)  =  force  (newton,  N)  x  distance  moved  in  

       

35  

the  direction  of  the  force  (metre,  m)  E  =  F  x  d  4.11  Be  able  to  demonstrate  an  understanding  that  energy  transferred  (joule,  J)  is  equal  to  work  done  (joule,  J)    

       

4.12  Know  that  power  is  the  rate  of  doing  work  and  is  measured  in  watts,  W    

       

4.13  Be  able  to  use  the  equation:    power  (watt,  W)  =  work  done  (joule,  J)  /  time  taken  (second,  s)  P  =  E  /  t  

       

4.14  Know  that  one  watt  is  equal  to  one  joule  per  second,  J/s            4.15  Be  able  to  use  the  equation:    gravitational  potential  energy  (joule,  J)  =  mass  (kilogram,  kg)  x  gravitational  field  strength  (newton  per  kilogram,  N/kg)  x  vertical  height  (metre,  m)  GPE  =  m  x  g  x  h  

       

4.16  Be  able  to  use  the  equation:    kinetic  energy  (joule,  J)  =  1/2  mass  (kilogram,  kg)  x  velocity2  ((metre/second)2,  (m/s)2)  KE  =  1/2mv2  

       

4.17  Be  able  to  demonstrate  an  understanding  of  the  idea  of  conservation  of  energy  in  various  energy  transfers    

       

4.18  HT  only:  Be  able  to  carry  out  calculations  on  work  done  to  show  the  dependence  of  braking  distance  for  a  vehicle  on  initial  velocity  squared  (work  done  to  bring  a  vehicle  to  rest  equals  its  initial  kinetic  energy).    

       

 

 

36  

P2.4  Exam  questions  –  41  marks,  41  minutes.  

Q15. A 60 kg student weighs 600 N. He does a bungee jump.

The bungee cord becomes straight and starts to stretch when he has fallen 50 m. (a) Complete the sentence by putting a cross ( ) in the box next to your answer.

He first stops moving (1)

A before all the energy has disappeared B before the bungee cord starts to stretch C when the bungee cord is stretched the most D when the elastic potential energy is zero (b) Complete the sentence by putting a cross ( ) in the box next to your answer.

When his speed is 10 m/s his momentum is

(1) A 600 kg m/s B 3 000 kg m/s C 6 000 N m/s D 30 000 N m/s (c) (i) Calculate the change in gravitational potential energy as the student falls 50 m. Give the unit.

(3)

.............................................................................................................................................. (ii) State at what point in the bungee jump the student has maximum kinetic energy.

(1) ..............................................................................................................................................

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37  

(iii) Explain why his maximum kinetic energy is likely to be less than your answer to (c)(i). (2)

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(Total for Question = 8 marks)

Q16. Andrew skis down a hill.

(a) Andrew starts from the top of the hill and his speed increases as he goes downhill. He controls his speed and direction by using his skis. He brings himself to a stop at the bottom of the hill. Describe the energy changes that happen between starting and stopping.

(3) ..............................................................................................................................................

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(b) Andrew returns to the top of the hill and starts again. (i) His mass is 67 kg.

Show that his momentum is about 2000 kg m/s when his velocity is 31 m/s. (2)

38  

(ii) He falls over when his momentum is 2000 kg m/s. After he falls over, he slows down by sliding across the snow. It takes 2.3 s for his momentum to reduce to zero. Calculate the average force on Andrew as he slows down.

(2)

.............................................................................................................................................. (iii) Andrew is not injured by the fall even though he was moving quickly. Use ideas about force and momentum to explain why he is not injured.

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(Total for Question is 9 marks)

39  

Q17. Momentum, energy and forces A box with a mass of 0.8 kg is lifted from the floor and placed on a shelf. The shelf is 1.8 m above the floor.

(a) (i) The box has gained gravitational potential energy. Calculate the gain in gravitational potential energy. Gravitational field strength = 10 N/kg

(2)

gain in gravitational potential energy = ......................................... J (ii) The box falls off the shelf. State the kinetic energy of the box just before it hits the floor.

(1) ....................................................................... J (iii) Just before the box hits the floor it has a momentum of 4.8 kg m/s. Calculate the velocity of the box just before it hits the floor.

(3)

velocity = ........................................ m/s

40  

*(b) The items in the box are packed in bubble wrap to protect them from damage.

Explain, by considering changes either in momentum or in kinetic energy, how bubble wrap protects the items in a box from damage caused by a fall.

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(Total for Question is 12 marks)

41  

Q18. A child is stationary on a swing.

(a) The child is given a push by his brother to start him swinging. His brother applies a steady force of 84 N over a distance of 0.25 m.

(i) Calculate the work done by this force.

(2)

.............................................................................................................................................. (ii) State how much energy is transferred by this force.

(1)

.............................................................................................................................................. (iii) After several more pushes, the child has a kinetic energy of 71 J. The mass of the child is 27 kg. Show that the velocity of the child at this point is about 2.3 m/s.

(2) (iv) Which one of these quantities changes in both size and direction while he is swinging? Put a cross ( ) in the box next to your answer.

(1) A his gravitational potential energy B his momentum C the force of gravity acting on him D his kinetic energy

42  

*(b) The brother then stops pushing the child. The graph shows how the kinetic energy of the child varies over the next few swings.

Explain the energy changes during this time.

(6)

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(Total for Question is 12 marks)

43  

P2.5  Specification  statements  To

pic   P2  Specification  Physics  for  your  future   RAG  

Curren

t   Revised  !  

1   2   3  

Topic  5:  Nuclear  Fission

 and

 nuclear  fu

sion

 

5.1  Be  able  to  describe  the  structure  of  nuclei  of  isotopes  using  the  terms  atomic  (proton)  number  and  mass  (nucleon)  number  and  using  symbols  in  the  format  146C    

       

5.2  Be  able  to  explain  how  atoms  may  gain  or  lose  electrons  to  form  ions.            

5.3  Know  that  alpha  and  beta  particles  and  gamma  rays  are  ionising  radiations  emitted  from  unstable  nuclei  in  a  random  process.    

       

5.4  Know  that  an  alpha  particle  is  equivalent  to  a  helium  nucleus,  a  beta  particle  is  an  electron  emitted  from  the  nucleus  and  a  gamma  ray  is  electromagnetic  radiation    

       

5.5  Be  able  to  compare  alpha,  beta  and  gamma  radiations  in  terms  of  their  abilities  to  penetrate  and  ionise.    

       

5.6  Be  able  to  demonstrate  an  understanding  that  nuclear  reactions  can  be  a  source  of  energy,  including  fission,  fusion  and  radioactive  decay.    

       

5.7  Be  able  to  explain  how  the  fission  of  U-­‐235  produces  two  daughter  nuclei  and  two  or  more  neutrons,  accompanied  by  a  release  of  energy.    

       

5.8  Be  able  to  explain  the  principle  of  a  controlled  nuclear  chain  reaction.            

5.9  Be  able  to  explain  how  the  chain  reaction  is  controlled  in  a  nuclear  reactor  including  the  action  of  moderators  and  control  rods.    

       

5.10  Be  able  to  describe  how  thermal  (heat)  energy  from  the  chain  reaction  is  converted  into  electrical  energy  in  a  nuclear  power  station.    

       

5.11  Know  that  the  products  of  nuclear  fission  are  radioactive.            

5.12  Be  able  to  describe  nuclear  fusion  as  the  creation  of  larger  nuclei  from  smaller  nuclei,  accompanied  by  a  release  of  energy  and  recognise  fusion  as  the  energy  source  for  stars.    

       

5.13  Be  able  to  explain  the  difference  between  nuclear  fusion  and  nuclear  fission.    

       

5.14  HT  only:  Be  able  to  explain  why  nuclear  fusion  does  not  happen  at  low  temperatures  and  pressures,  due  to  electrostatic  repulsion  of  protons.    

       

5.15  HT  only:  Be  able  to  relate  the  conditions  for  fusion  to  the  difficulty  of  making  a  practical  and  economic  form  of  power  station.    

       

5.16  Be  able  to  demonstrate  an  understanding  that  new  scientific  theories,  such  as  ‘cold  fusion’,  are  not  accepted  until  they  have  been  validated  by  the  scientific  community.    

       

 

   

44  

P2.5  Exam  Questions  –  43  marks,  43  minutes.  

Q19. Alpha, beta and gamma are types of ionising radiation.

(a) State two ways in which gamma radiation is different from alpha radiation.

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.............................................................................................................................................. (b) (i) Complete the sentence by putting a cross ( ) in the box next to your answer.

A beta particle is emitted by

(1) A an alpha particle B a fusion particle C a gamma ray D an unstable nucleus

(ii) Complete the sentence by putting a cross ( ) in the box next to your answer. A beta particle has an identical charge to

(1) A an alpha particle B an electron C a neutron D a nucleus (c) Explain how an atom becomes ionised by radiation.

(2) ..............................................................................................................................................

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45  

*(d) The removable lens of this old camera has four pieces of glass in it.

One of the pieces of glass is radioactive. Its surface is covered with a thin layer of magnesium fluoride. Radioactive isotopes in the glass emit alpha, beta and gamma radiation in all directions. A scientist removes the lens from the camera. She measures the radiation coming from the back, front and side of the lens. The amount of radiation is different in each direction. No alpha radiation is detected. The readings are shown on the diagram.

Explain why the readings in the three directions are different.

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(Total for Question is 12 marks)

47  

Q20. (a) Two isotopes of uranium are U-235 and U-238.

Here are the symbols of the nuclei of these isotopes.

(i) Complete the sentence by putting a cross ( ) in the box next to your answer. The U-235 isotope has

(1) A the same number of neutrons as U-238 B the same number of protons as U-238 C more neutrons than U-238 D more protons than U-238

(ii) U-235 is radioactive. When it decays, it releases an alpha particle. Describe an alpha particle.

(2) ..............................................................................................................................................

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.............................................................................................................................................. (b) U-235 can also be made to undergo fission. Describe what happens during nuclear fission.

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(c) Fission is used in nuclear reactors. Graphite is used as a moderator in nuclear reactors. Explain why a moderator is needed in a nuclear reactor.

(2) ..............................................................................................................................................

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(Total for Question is 9 marks)

49  

Q21. Nuclear reactions (a) Complete the sentence by putting a cross ( ) in the box next to your answer. Two types of nuclear reaction are nuclear fission and nuclear fusion. Nuclear fission and nuclear fusion reactions both

(1) A combine hydrogen nuclei B combine uranium nuclei C release neutrons D release energy

(b) In 1989, two scientists called Pons and Fleischmann claimed to have produced ‘cold fusion’. Their claim has never been validated by the scientific community. Explain the phrase validated by the scientific community.

(2) ..............................................................................................................................................

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(c) Nuclear fusion is the main energy source for stars. Describe what happens in nuclear fusion.

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*(d) Describe how the nuclear fission of uranium-235 is used to produce electricity in a nuclear power station.

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(Total for Question is 12 marks)

51  

Q22.

Uranium-238 is an isotope of uranium. It may undergo either radioactive decay or nuclear fission. A nucleus of uranium-238 is shown as Q in the chart.

(a) State two letters from the chart which show isotopes of the same element.

(1) ..............................................................................................................................................

(b) Explain what happens when Q decays to P.

(2) ..............................................................................................................................................

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(c) Explain what happens when P decays to O. (2)

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52  

(d) Particles released during radioactive decay can have different energies. A suitable unit for these energies is MeV. For one type of decay, the particles released have energies between 4.0 MeV and 10.0 MeV. The graph shows how far the particles with these energies travel in air.

(i) State the name of this type of particle.

(1) .............................................................................................................................................. (ii) Use information from the graph to describe how the distance travelled in air depends on the energy of the particle.

(2) ..............................................................................................................................................

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(e) Uranium-238 can only undergo nuclear fission by absorbing fast neutrons. The fission emits neutrons which very quickly lose their energy.

Suggest why the fission of uranium-238 does not produce a chain reaction. (2)

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(Total for Question = 10 marks)

53  

P2.6  Specification  statements    To

pic   P2  Specification  Physics  for  your  future   RAG  

Curren

t   Revised  !  

1   2   3  

 Top

ic  6:  A

dvan

tages  a

nd  disad

vantages  of  u

sing

 radioa

ctive  materials  

6.1  Be  able  to  explain  what  is  meant  by  background  radiation,  including  how  regional  variations  within  the  UK  are  caused  in  particular  by  radon  gas.    

       

6.2  Know  the  origins  of  background  radiation  from  Earth  and  space.    

       

6.3  Be  able  to  describe  uses  of  radioactivity,  including:            a)  household  fire  (smoke)  alarms            b)  irradiating  food            c)  sterilisation  of  equipment            d)  tracing  and  gauging  thicknesses            e)  diagnosis  and  treatment  of  cancer            6.4  Be  able  to  describe  how  the  activity  of  a  radioactive  source  decreases  over  a  period  of  time.    

       

6.5  Know  that  the  unit  of  activity  of  a  radioactive  isotope  is  the  Becquerel,  Bq.    

       

6.6  Know  that  the  half-­‐life  of  a  radioactive  isotope  is  the  time  taken  for  half  the  undecayed  nuclei  to  decay.    

       

6.7  Be  able  to  use  the  concept  of  half-­‐life  to  carry  out  simple  calculations  on  the  decay  of  a  radioactive  isotope,  including  graphical  representations.    

       

6.8  Revise  any  investigations  on  models  which  simulate  radioactive  decay.    

       

6.9  Be  able  to  demonstrate  an  understanding  of  the  dangers  of  ionising  radiation  in  terms  of  tissue  damage  and  possible  mutations  and  relate  this  to  the  precautions  needed.    

       

6.10  Be  able  to  describe  how  scientists  have  changed  their  ideas  of  radioactivity  over  time,  including:    

       

a)  the  awareness  of  the  hazards  associated  with  radioactive  sources    

       

b)  why  the  scientific  ideas  change  over  time            6.11  Be  able  to  discuss  the  long-­‐term  possibilities  for  storage  and  disposal  of  nuclear  waste.    

       

6.12  Be  able  to  evaluate  the  advantages  and  disadvantages  of  nuclear  power  for  generating  electricity,  including  the  lack  of  carbon  dioxide  emissions,  risks,  public  perception,  waste  disposal  and  safety  issues.    

       

     

54  

P2.6  Exam  Questions  –  41  marks,  41  minutes.  

Q23. Carbon-14 is a radioactive isotope that occurs naturally. Scientists use carbon-14 to help find the age of old pieces of wood. This technique is called carbon dating. It uses the idea of half-life. (a) Which of these describes half-life? Put a cross ( ) in the box next to your answer.

(1) A the time it takes for half of the undecayed nuclei to decay B the time it takes for all of the undecayed nuclei to decay C half the time it takes for all of the undecayed nuclei to decay D half the time it takes for half of the undecayed nuclei to decay

(b) Sketch a graph to show how the activity of a radioactive isotope changes with time.

Use the axes below. Start your line from point P. (3)

55  

(c) A scientist investigates an old wooden comb.

The activity of the carbon-14 in it is 0.55 Bq. The estimated age of the comb is 11 400 years. The half-life of carbon-14 is 5700 years. (i) Calculate the activity of the carbon-14 in the comb when it was new.

(3)

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.............................................................................................................................................. (ii) The scientist takes several readings of background radiation. Explain why this is necessary to improve the accuracy of the investigation.

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.............................................................................................................................................. (iii) Old objects like the comb emit a very small amount of radiation. The activity from the comb is about the same as comes from background radiation. Scientists have stopped measuring the activity of carbon-14 for carbon dating. Instead, they can measure the mass of undecayed carbon-14 left in the sample. Suggest a reason for this change.

(1) ..............................................................................................................................................

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(Total for Question is 10 marks)

56  

Q24.

(a) A scientist uses a Geiger counter to measure the radioactivity of a sample.

She writes down the results in her notebook. The Geiger counter gives a count rate of 120 counts per minute. The average background radiation in her laboratory is 10 counts per minute. (i) What should she write down for the count rate of this sample? Put a cross ( ) in the box next to your answer.

(1) A 12 counts per minute B 110 counts per minute C 130 counts per minute D 1200 counts per minute

(ii) Name one source of background radiation.

(1) .............................................................................................................................................. (iii) Explain why some people are exposed to more background radiation than others.

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(iv) Complete the sentence by putting a cross ( ) in the box next to your answer. The recommended safe limit for exposure to radiation has been reduced over the last 80 years. This is because now

(1) A better instruments allow scientists to make measurements more quickly B global warming has increased the rate of decay of radioactive materials C humans release more radioactive materials into the environment D scientists have a better understanding of the dangers of radiation

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(b) After the accident at the Fukushima nuclear plant in Japan, some drinking water became contaminated with radioactive iodine-131. The graph shows how the activity of a sample of iodine-131 changes over two weeks.

(i) Use the graph to estimate the half-life of the iodine-131. Show your working clearly.

(2)

.............................................................................................................................................. (ii) The recommended safe limit for a sample of this size is 100 Bq. How long did it take for the activity of the sample to decay until it was below the safe limit?

(1)

.............................................................................................................................................. (iii) When iodine-131 decays, it emits beta radiation. State one possible danger to health from exposure to beta radiation.

(1) ..............................................................................................................................................

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(Total for Question is 9 marks)

58  

Q25. Radioactivity, its uses and problems (a) Radioactivity is used in medicine to diagnose and treat cancer. State two other uses of radioactivity.

(2) ..............................................................................................................................................

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.............................................................................................................................................. (b) Which of these is the correct definition for the half-life of a radioactive isotope? Put a cross ( ) in the box next to your answer.

(1) A it is the time it takes for half of an atom to decay B it is the number of atoms left when half have decayed C it is the time taken for half the undecayed nuclei to decay D it is half of the time it takes for all the undecayed nuclei to decay (c) (i) Iodine-131 emits beta particles. State what a beta particle is.

(1) ..............................................................................................................................................

.............................................................................................................................................. (ii) The graph shows how the activity of iodine-131 varies with time.

A sample of iodine-131 has a mass of 100 mg. How much iodine-131 will remain after 24 days?

(3)

mass of iodine-131 = ...................................... mg

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(d) Scientists in Finland are building a facility for the storage of radioactive waste. They plan to bury radioactive waste deep underground. Describe some of the issues that need to be considered when planning to bury nuclear waste.

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(Total for Question is 10 marks)

60  

Q26. (a) An underground oil pipe starts to leak oil. To find the leak, a technician adds a gamma source to the oil flowing in the pipe. Describe how the technician can find the position of the leak.

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(1) A It is half the time for all the atoms to decay B It is the time it takes for an atom to half decay C It is the time it takes for half an atom to decay D It is the time it takes for half the atoms to decay

(c) The graph shows how the activity of a sample of a radioactive material changes with time. The sample has an initial activity of 80 counts per minute.

(i) Use the graph to find the half-life of the material.

(1)

.............................................................................................................................................. (ii) Another sample of the material has an initial count rate of 40 counts per minute.

Sketch, on the same axes, the activity of this sample for the first 4 days. (2)

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*(d) Some scientists carry out an experiment to measure the radioactivity from a source to be used in a factory. They measure the background radiation before and after their experiment. They take the background count at the same place as they do their experiment. Explain how this procedure helps to make sure that the results of the experiment are valid.

(6)

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(Total for Question = 12 marks)

62  

Top  ten  tips  

Tip  1:  Plan  your  revision  

Create  a  realistic  and  well-­‐presented  timetable  which  you  will  adhere  to.  Include  exam  dates  and  deadlines  for  coursework.  Add  in  sports/social/family  commitments.  Show  it  to  your  parents;  get  them  to  add  in  dates  you  might  not  know  about.  

If  you  have  a  block  of  exams,  plan  for  them.  If  you  have  three  exams  in  three  days,  you  will  need  to  be  prepared  to  walk  into  the  last  exam  before  you  walk  into  the  first.  For  block  exams  create  one  page  revision  reminder  notes  which  allow  you  to  review  the  whole  course  in  a  short  space  of  time.  

Give  priority  to  the  exams  which  are  worth  the  most  to  you,  or  you  need  to  spend  the  most  time  on.  

Tip  2:  get  a  revision  guide  for  your  course  

Tip  3:  print  off  all  the  past  papers  AND  mark  schemes  possible.  Use  half  the  papers  during  revision,  and  half  to  test  your  knowledge  throughout.  

Tip  4:  Contact  your  teacher  so  they  can  help  when  you  get  stuck  (a  lot)  

Tip  5:  get  the  right  environment:  

o no  distractions  (no  music,  Facebook,  tv,  family  and  friends)  o not  too  hot  (cold  temperature  keeps  your  body  awake  open  a  window  if  necessary)  o comfortable  o space  or  organisation  (don’t  get  your  papers  all  muddled  up)  o paper  to  write  notes  o pens/pencils  

Tip  6:  Segment  your  revision  of  a  subject.  Don’t  try  to  revise  all  of  the  subject  at  once.  Select  one  section,  revise  it,  learn  it,  and  find  all  the  questions  you  can  on  that  knowledge  to  test  it.  

Tip  7:  Revise  smart.  Don't  revise  for  more  than  your  brain  can  cope  with.  You  need  to  be  aware  of  when  it  has  stopped  going  in.  I  always  found  around  40-­‐50  mins  hard-­‐core  revision  was  the  most  useful  time.  Then  take  short  useful  breaks,  use  a  different  part  of  your  brain,  try  doing  something  physical  (don’t  get  onto  blackops  as  you  won’t  get  off  it  again).  Take  10  minute  breaks.  

Tip  8:  Nap!,  believe  it  or  not,  you  will  boost  the  amount  you  can  learn  in  one  day  by  30%+  just  by  taking  short  naps  (10-­‐20  mins).  Set  an  alarm  though!  This  is  because  what  you  have  learnt  goes  from  your  long  term  to  your  short  term  memory  

Tip  9:  Don't  think  you  know  it,  test  it.  Doing  questions  is  the  only  way  of  testing  your  application  of  knowledge.  This  is  easier  in  some  subjects  than  others.  Science  and  Maths  there  is  no  excuse  for  not  doing  loads  of  practise  questions.  Mark  those  questions  using  answers,  check  you  have  answer  before  even  attempting  questions  as  it  will  be  useless  otherwise.  

Tip  10:  follow  my  previous  nine  tips