JC1 Promotional Examination 2014 - PBworks

© JJC 2014 8866/JC1 Promo P1/2014 [Turn Over

JURONG JUNIOR COLLEGE JC1 Promotional Examination 2014

Name Class 15S

PHYSICS Higher 1

Multiple Choice

Additional Materials: Multiple Choice Answer Sheet Soft clean eraser Soft pencil (type B or HB is recommended)

8866/1

24 September 2014

1 hour

READ THESE INSTRUCTIONS FIRST Do not open this booklet until you are told to do so. Write your name and class in the spaces provided at the top of this page. Shade in soft pencil. Do not use staples, paper clips, highlighters, glue or correction fluid. Write your name, class and index number on the Answer Sheet in the spaces provided. There are thirty questions in this paper. Answer all questions. For each question there are four possible answers A, B, C and D. Choose the one you consider correct and record your choice in soft pencil on the separate Answer Sheet. Each correct answer will score one mark. A mark will not be deducted for a wrong answer.

(This question paper consists of 16 printed pages)


2

Data

speed of light in free space, c = 3.00 x 108 m s-1

elementary charge, e = 1.60 x 10-19 C

the Planck constant, h = 6.63 x 10-34 J s

unified atomic mass constant, u = 1.66 x 10-27 kg

rest mass of electron, me = 9.11 x 10-31 kg

rest mass of proton, mp = 1.67 x 10-27 kg

acceleration of free fall, g = 9.81 m s-2

Formulae

uniformly accelerated motion, s = ut + ½at2

v2 = u2+ 2as

work done on/by a gas, W = pV

hydrostatic pressure, p = gh

resistors in series, R = R1 + R2 + …

resistors in parallel, 1/R = 1/R1 + 1/R2 + …

3


1 Which pair contains one vector and one scalar quantity?

A torque and kinetic energy

B displacement and acceleration

C momentum and velocity

D power and speed

2 A student takes 5 readings of the diameter of a rod: 5.6 mm, 6.3 mm, 5.9 mm, 6.6 mm, 6.2 mm. The actual diameter of the rod is 5.0 mm.

Which of the following best describe the errors in the readings?

Random error Systematic error

A low low

B low high

C high low

D high high

3 A car is travelling at a velocity of 34 m s-1 due west initially. At a later time, it is seen travelling at a velocity of 20 m s-1 due south.

Given that the direction North N, points vertically towards the top of the page, which of the following vector represents the change in velocity of the car?

A

B

C

D

R

N

R

N

R

N

R

N

4


4 A car is travelling at its cruising speed on an expressway. It is then brought to rest.

Which value is the best estimate of the car's change of momentum?

A 3 x 103 kg ms-1

B 3 x 104 kg ms-1

C 3 x 105 kg ms-1

D 3 x 106 kg ms-1

5 The maximum kinetic energy, KE of an electron in the photoelectric effect is given as

KE = hf - .

Which statement must be correct for the equation to be homogenous?

A KE, h, f and all have the same units

B KE, h, f and are all scalar quantities

C The product hf has the same units as KE and

D The product hf is numerically equal to (KE + )

6 An antelope is running in a straight line along the East-West direction, with the positive direction to the East. The figure below shows this animal’s velocity as a function of time.

Which of the following statements about the animal’s motion must be true?

A Its speed is increasing at a uniform rate.

B Its acceleration is increasing.

C It is moving to the East between a and c.

D It is moving to the West between a and b and to the East between b and c.

a

0 b t / s

v / m s-1

c

5


7 A cyclist is initially at rest on a downward slope which leads to a horizontal road.

The cyclist does not pedal or apply the brakes, but allows the bicycle to freewheel down the slope and along the horizontal road. The cyclist experiences a constant resistive force.

Which graph best represents the way the cyclist’s velocity v varies with time t?

A

B

C

D

6


8 A multiple exposure photograph is taken for a sphere dropping vertically. The time interval between each pair of successive exposures is always the same.

Taking downwards as positive, which graph best represents, the motion of the sphere during this period?

A

B

C

D

7


9 The average speeds of a car, accelerating uniformly through three stages, are as shown.

What is the overall average speed of the car?

A 12 m s-1

B 13 m s-1

C 40 m s-1

D 48 m s-1

10 A projectile moves in a parabolic path as shown in the displacement-distance graph below.

At which point along its path are the velocity and acceleration vectors perpendicular to each other?

20.0 m s-1 for 2.0 s 40.0 m s-1 for 2.0 s 60.0 m s-1 for 6.0 s

D

C

y / m

A

B

x / m

8


11

The graph shows the variation with extension x of the load F on a certain spring.

0

5

10

15

20

25

0.00 0.02 0.04 0.06 0.08 0.10

x / m

F /

N

A load of 10 N is placed on the spring.

How much additional elastic potential energy will be stored in the spring if it is then extended a further 0.040 m?

A 0.200 J B 0.450 J C 0.600 J D 0.800 J

12

A long and thin L-shaped tube is filled with liquid to the depth as shown in the figure below. The pressure at X due to the liquid alone is P. The tube is then rotated by an

angle of 45.

The pressure exerted at X due to the liquid is now

A 1

2P B P C 2 P D 2 P

9


13

Two forces P and Q act at a point X as shown in the vector diagram below.

In which of the following diagrams does the vector F represent the force which must be applied at X to maintain equilibrium?

A

B

C

D

14 A weight W is supported by two light strings inclined at 30° and 60° to the vertical. The tensions in the strings are T1 and T2.

Determine the ratio 1

2

T

T.

A 3 B 2

3 C 1 D

3

1

10


15

A small metal sphere of mass m is falling vertically through a viscous fluid.

When it reaches a constant velocity v, which of the following statements is false?

A The kinetic energy is constant and equal to ½ mv2

B The gravitational potential energy decreases at a rate of mgv

C The total mechanical energy of the sphere is constant

D The resistive force acting on the sphere is constant

16

The drawing below shows a wine rack for a single bottle of wine that seems to defy

common sense as it balances on a table top.

Which of the following shows the correct forces acting on the wine rack holder?

A

B

C

D

11


17

A number of forces are acting on the objects below.

(i)

(ii)

(iii)

Which of the objects above is/are in rotational equilibrium?

A (i) only

B (ii) only

C (iii) only

D (ii) and (iii)

18 Which of the following statements is always true?

A If an object does not experience acceleration, there are no forces acting on it.

B If an object experiences acceleration, there must be at least one external force acting on it.

C If an object’s kinetic energy remains constant, there are no forces acting on it.

D If an object’s gravitational potential energy remains constant, there are no forces acting on it.

12


19 A helicopter of mass 3.0 × 103 kg rises vertically with a constant speed of 25 m s1.

Taking the acceleration of free fall to be 10 m s2, what is the lift force acting on the helicopter?

A 0 N

B 3.0 × 104 N

C 7.5 × 104 N

D 11 × 104 N

20 An object of mass m is hanging by a string from the roof of a lift. The lift is moving upward, but slowing down.

Which of the following statement best describe the tension in the string?

A Tension is less than mg.

B Tension is equal to mg.

C Tension is greater than mg.

D Tension is zero.

21 A car with front-wheel drive accelerates in the direction shown.

Which diagram best shows the direction of the resultant force exerted by the road on the front wheels?

A

B

C

D

13


22 Two objects P and Q are originally held together at rest with a compressed light spring between them. P has a larger mass compared to Q.

Which of the following statements is correct about the motion of P and Q upon release and the light spring is allowed to extend? Assume there is no friction.

A P has less kinetic energy than Q.

B P has a smaller momentum than Q.

C P has a larger acceleration than Q.

D The magnitude of the velocities of P and Q are equal.

23 The graph below shows the force acting on a body of 2.0 kg over a period of 4.0 s.

If the body was initially moving at 1.0 m s-1, what would be its velocity after 4.0 s?

A 10 m s-1

B 11 m s-1

C 20 m s-1

D 21 m s-1

P Q

Force / N

time / s

10

0

2 4

14


24 A body initially at rest explodes into two fragments, one having four times the mass of the other.

What is the value of the ratio momentum of more massive fragment

momentum of less massive fragment?

A 0.20

B 0.25

C 1.00

D 4.00

25 A forklift raised a load of mass m to a height h above the ground in time t at a constant rate.

Which of the following statement is false?

A The gain in gravitational potential energy of the load is mgh.

B The rate of work done by the forklift in lifting the load is constant.

C The kinetic energy of the load is given by 21

( )2

hm

t

D Work done by the forklift is converted to increase in gravitational potential energy and the increase in kinetic energy of the load.

26 The engine of an inter-city train delivers a power of 2 MW while travelling at a speed of 50 m s

-1

What is the tractive force exerted by the engine?

A 4 x 104 N B 1 x 105 N

C 4 x 107 N D 1 x 108 N

15


27 A fixed mass of gas undergoes changes of pressure and volume as shown in the figure below.

When the gas is taken from state R to state Q by the stages RS ad SQ, the total work done by the gas is

A zero B 1.5 J

C 9.0 J D 1.5 x 106 J

28 A box of weight 100 N is pushed 10 m up a slope inclined at 30° above the horizontal by a force of 150 N along the slope. The frictional force opposing the motion is 60 N.

How much of the work done by the 150 N force is converted into kinetic energy and thermal energy?

Kinetic Energy / J Thermal Energy / J

A 400 600

B 900 600

C 400 0

D 600 900

Q

30

60 N 150 N

10 m

S R

Pressure p / 105 Pa

Volume V / cm3

7

1

5 20

16


29 In the diagram below, a 50 g ball at point A is projected horizontally along a smooth

surface with a velocity of 4.2 m s1, where it encounters a spring at its natural length. The

spring has a spring constant of 120 N m1.

What is the maximum compression of the spring?

A 2.7 mm

B 7.4 mm

C 3.0 cm

D 8.6 cm

30 A motor driving a pump raises 0.10 m3 of water through a vertical height of 5.0 m in a time of 10 minutes.

If the efficiency of the motor is 60%, what is the power supply by the motor?

Density of water is taken to be 1000 kg m3

A 4.9 W

B 8.2 W

C 14 W

D 490 W

End of Paper

A

0.200 m

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