Sample Problem1. An object is moving along a horizontal path as

shown below with a speed which is uniformly decreasing in magnitude. Which of the following arrows shows the direction of the object’s acceleration (if any)?

A. ↑B. ↓C. → D. ← E. The acceleration is zero because the motion is

uniform.

►

Paradigm: car braking

Sample Problem2. Suppose that a sound wave in a particular

medium has a frequency of 104 Hertz and a velocity of 1250 m/s. What is the wavelength of the sound?

A. 0.125 mB. 8 mC. 12.5 mD. 80 mE. 1.25 × 107 m

►

Paradigm: Wave

m 125.0s 10m/s 1250

1-4 fv

Sample Problem3. The equation x = sin 2t describes the simple

harmonic motion of a particle. What is the amplitude of the motion?

A. 1/4B. 1/2C. 1D. 2E. 4

►

Paradigm: Wave

Sample Problem4. Starting with a velocity of 3 m/sec, a sphere

accelerates at a rate of 1 m/sec2 for two seconds. How far does the sphere move during the two second period?

A. 6 mB. 7 mC. 8 mD. 10 mE. 12 m

►

Paradigm: Braking Car

m 862

23210 221

02

21

0

xtvatxx

Sample Problem5. A 75 kg rock is dropped from a 40 meter cliff.

While the rock is falling, the air exerts a frictional force of 50 N on the rock. What work is done on the rock by the frictional force?

A. -1000 JB. -1500 JC. -2000 JD. -3000 JE. None of the above; work cannot be done by a

disembodied force in midair.

►

Paradigm: Block on plane

.directions opposite in arent displacemeand force thefact that thefrom comes sign - the

J 2000m 40N 50 dfW

Sample Problem6. A body is in translational equilibrium if it is

A. at rest only.B. moving with a constant velocity only.C. moving with constant acceleration only.D. either at rest or moving with a constant velocity.E. moving with either a constant velocity or a constant

acceleration.

►

Paradigm: lifting a box

Sample Problem7. Starting from the same height, two small objects of equal mass

slide down the two frictionless inclined planes A and B shown in the figure. The object down plane A reaches the foot of the plane with final velocity vA, and the object sliding down plane B reaches the bottom with final velocity vB. What is the magnitude of the ratio vB / vA?

A. ½B. 1C. 2D. 4E. 8

►

Paradigm: Block on plane

h h

1 m 2 m

A B

Sample Problem8. A 3-lb block is placed on top of a 5-lb block

that is in a stable position on a table. What is the magnitude of the force (if any) exerted by the table on the 5-lb block?

A. 0 lbB. 2 lbC. 3 lbD. 5 lbE. 8 lb►

Paradigm: Lifting a box

5 lb

3 lb

5 lb

3 lb

8 lb

Sample Problem9. When 13Al27 is bombarded with neutrons under

certain conditions, a neutron is absorbed and an alpha particle (2He4) is emitted. What is the other product?

A. 13Al28

B. 12Mg24

C. 12Mg23

D. 11Na24

E. 11Na23

►

Paradigm: C14 decay

42

??

10

2713 He?nAl

42

2411

10

2713 HeNanAl

Sample Problem10. Suppose that it takes 8 days for the

radioactivity of a particular sample to decrease to 1/8 of the initial value. Approximately what is the magnitude of the half-life of the sample?

A. 1 dayB. 2 daysC. 2.7 daysD. 4 daysE. Cannot be determined by the information given.

►

Paradigm: C14 decay

days 2.7days 322

3days 8 So elapsed. have

lives-half 3 so value,original its of 21

81 isactivity The

21

3

t

Sample Problem11. An electric charge q is placed in an electric

field. The magnitude of the charge and the strength of the field are both known. What, if any, additional information is needed to calculate the force on the charge?

A. The distances from q to other charges in the field.B. The distances from q to the charges producing the

field.C. Whether the field is produced by point charges or

parallel plates.D. None of the above.►

Paradigm: Charge in Capacitor

Sample Problem12. Suppose that I3, the current in the 8-Ω resistor,

is 0.4 Amperes. What is I, the total current?A. 0.7 AB. 1.2 AC. 2.4 AD. 2.8 AE. Cannot be determined by the information given.

►

Paradigm: Series-Parallel circuits

A 8.24.07A 4.04) 2 (1 iscurrent totalTheresistor. 4 thein that twicehasresistor 2 The

resistor 8 theascurrent the twicehasresistor 4 The

8 Ω4 Ω2 Ω I3I2

I1

I

Sample Problem13. Suppose that a ray of light strikes the interface

between two media whose indices of refraction are given by n1=1.6 and n2=1.2 and that sin θ1 = 0.5. Which of the following gives the angle of refraction θ3?

A. sin θ3 = 1/3B. sin θ3 = 3/8C. sin θ3 = 1/2D. sin θ3 = 2/3E. sin θ3 = 3/4

►

Paradigm: Car into sand

32

21

34

21

2.16.1sinsin

sinsin

12

13

3211

nn

nn

n1 n2

θ1

θ2 θ3

Sample Problem14. A large metal sphere and a small metal sphere, each charged

positively, are connected by a copper wire. The charges are at rest. What conclusion can be drawn about the potentials P1 and P2 of the spheres?

A. P1 is higher than P2.B. P1 is equal to P2.C. P1 is lower than P2.D. Any of the above may be true depending on the length of the wire.E. Any of the above may be true depending on the original charges of

the spheres

►

Paradigm:

P2P1

Sample Problem15. The wavelength of the radiation of maximum intensity

emitted by a hot metallic element in the solid state is dependent on

A. the roughness of the surface.B. the temperature of the surface.C. the atomic weight of the element.D. The atomic number of the element.E. none of the above.

►

Paradigm:

Sample Problem16. Suppose that an object is placed at point X near a

convex mirror, as shown in the figure above. The distance between point X and the mirror is equal to the radius of curvature of the mirror. Where will the image be located?

A. In region 1B. At point XC. In region 2D. In region 3E. Cannot be determined from the information given.

►

Paradigm: lenses and mirrors

RRRofi312111

region 1 region 2 region 3

negative bemust so negative, is 111 ifofi

There are 3 ways to come up with the correct answer.

Sample Problem17. Suppose that a rocket is orbiting a planet in a circular

orbit, as shown below. Which of the lettered arrows shows the direction of the acceleration of the rocket?

A. AB. BC. CD. DE. None of the above

►

Paradigm: Braking Car

A

B

C D

Sample Problem18. Which of the following is the missing species

required to balance the equation below?A. 47Ag106

B. 48Cd107

C. 49In106

D. 49In114

E. The equation cannot be balanced.

►

Paradigm: C14 decay

01

10648 eCd

19. Consider the following hydraulic system viewed from above with all of the pistons in the same horizontal plane.

To exert the greatest amount of force on piston C, one should exert a force of 8 N on a

A. Large piston at position A only.B. Large piston at positions A or B.C. Small piston at position A only.D. Small piston at positions A or B.

Sample Problem

►

Paradigm: Water Tank

AB

CA

Sample Problem20. Blood is flowing through an artery in a heart. There is

an atherosclerotic plaque in the artery which narrows the artery to half its initial diameter. The ratio of the speed of blood flow at point A, in the wide region of the artery, to the speed at point B, in the narrowed region, will be

A. 1/4B. 1/2C. 1D. 2E. 4

►

Paradigm: Water Tank

A B

41

21

2

2

21

22

1

2

2

12

1

212211

rr

AA

vvv

AAvvAvA

Sample Problem21. Suppose that an object is lifted vertically each

of the distances shown below at a constant speed, in the time periods given.

• Case I: 2 m; 2 sec.• Case II: 4 m; 1 sec.In which case is the average power employed greater?A. Case IB. Case IIC. Same in both casesD. Cannot be determined from the information given

►

Paradigm: Porsche

tmgh

tWP

vFtxF

tWP

Sample Problem22. Sound intensity is usually measured in decibels, .

The decibel is defined as b = 10 log(I/I0), where I is the intensity of the sound and I0 is an arbitrary reference level. If one jet airplane produces a sound level of 100 decibels, what sound level is produced by two jets? (Log 2 = 0.30)

A. 103 decibelsB. 130 decibelsC. 200 decibelsD. 300 decibelsE. Cannot be determined from the given information.

►

Paradigm: Waves

1031003db so,

/log102log10/2log10/log10

new

000

IIIIIIdB

+3 db always represents a doubling of power-3 db always represents a halving of power

Sample Problem23. A sound wave from a stationary observer is

bounced off an object approaching with velocity v. The reflected wave, relative to the original wave, has

A. decreased frequency, increased velocity.B. same frequency, same velocity.C. same frequency, increased velocity.D. increased frequency, same velocity.E. increased frequency, increased velocity.

►

Paradigm: Waves

Sample Problem24. The half-life of an unstable radioactive element

is 0.5 seconds. How much of 1600 micrograms will be left after 3 seconds? The atomic mass of the isotope is 247.

A. 400 μgB. 266 μgC. 130 μgD. 50 μgE. 25 μg►

Paradigm: C14 decay

3 seconds is 6 half-livesThis represents 6 divisions by 2So m=1600/26 = 1600 / 64 = 25 g

Sample Problem25. An x-ray machine accelerates electrons through a potential

difference of 15,000 V after which they impact on a metal plate. As the electrons slow down they give off energy as x-rays in a process called bremsstrahlung. (Braking radiation in German.) If there are 10 mA of electron current in this machine, how much power must be supplied by the power supply in the machine?

A. 10 mWB. 15 WC. 100 WD. 150 WE. Not enough information is given to determine an answer.

►

Paradigm: series-parallel circuit

W 1501510V 000,15mA 10 IVP