**MULTIPLE CHOICE. Choose the one alternative that best
completes the statement or answers the question.**

1) The work done by the
centripetal force on an object with a mass of 1 kg moving with a constant
velocity of 4 m/s into a circular path of radius 0.6 m for one full cycle is

A) 100.7 J B) 3.8 J C) 0 J D) 80 J

Answer: C

2) A truck has four times the mass of a car and is
moving with twice the speed of the car. If K_{t} and K_{c}
refer to the kinetic energies of truck and car respectively, it is correct to
say that

A) K_{t} = 16K_{c} B) K_{t} = 4K_{c} C) K_{t} = K_{c} D) K_{t} = 1/2 K_{c}

Answer: A

**Figure 7-4**

** **

3) An object is under the influence of a force as
represented by the force vs. position graph in Figure 7-4. What is the work
done as the object moves from 6 m to 12 m?

A) 20 J B) 30 J C) 0 J D) 40 J

Answer: B

4) A car accelerates from rest to a speed of 20.0 m/s in 6.00 seconds. If the car weighs
16,000 N, what average power must the motor produce to cause this acceleration?

A) 128 kW B) 15.0 kW C) 54 .4
kW
D) 219 kW

Answer: C

**A mass of 1.0 kg is
pushed against a spring with a spring constant of 25 N/m. As a result, the
spring is compressed by 20 cm. The mass is then released.**

5) What is the amount of work required to compress the
spring?

A) 5.0 J

B) 0.20 J

C) 0.50 J

D) 10 J

Answer: C

6) An object of mass *m* is held at a
vertical height *h* from ground
level. It is then released and falls under the influence of gravity. Which of
the following statements is true in this situation? (Neglect air resistance.)

A) The total energy of the
object is decreasing.

B) The kinetic energy of
the object is decreasing.

C) The total energy of the
object is increasing.

D) The potential energy of
the object is decreasing and the kinetic energy is increasing.

Answer: D

**Figure 8-7**

** **

** **

** **

An object with a
mass of 10.0 kg is at rest at the top of a frictionless inclined plane of
height 8.00 m and an angle of inclination 30.0e with the horizontal. The object
is released from this position and it stops at a distance *d* from the
bottom of the inclined plane along a horizontal surface, as shown in Figure
8-7. The coefficient of kinetic friction for the horizontal surface is 0.400
and *g* = 10.0 m/ s to power of (exponent).

7) Refer to Figure 8-7. What is the kinetic energy of
the object at the bottom of the inclined plane?

A) 400 J

B) 500 J

C) 700 J

D) 800 J

Answer: D

**Figure 8-10**

**2-kg mass is moving
along the x axis. The potential energy curve as a function of position
is shown in Figure 8-10. The system is conservative. There is no friction.**

8) Refer to Figure 8-10. If the object is at rest at the
origin, what will be its speed at 9.0 m along the +*x*-axis?

A) 1.5 m/s

B) 2.5 m/s

C) 3.5 m/s

D) 4.5 m/s

Answer: C

9) A golf club exerts an average force of 1000 N on a
0.045-kg golf ball which is initially at rest. The club is in contact with the
ball for 1.8 ms. What is the speed of the golf ball as it leaves the tee?

A) 35 m/s

B) 40 m/s

C) 45 m/s

D) 50 m/s

Answer: B

10) In a collision between two unequal masses, how does
the impulse imparted to the smaller mass by the larger mass compare with the
impulse imparted to the larger mass by the smaller one?

A) It is larger.

B) It is smaller.

C) They are equal.

D) The answer depends on
how fast they are moving.

Answer: C

11) An elastic collision of two objects is characterized
by the following.

A) Total momentum of the
system is conserved.

B) Total kinetic energy of
the system remains constant.

C) Both A and B are true.

D) Neither A nor B are
true.

Answer: C

12) A uniform piece of wire, 20 cm long, is bent in a
right angle in the center to give it an L-shape. How far from the bend is the
center of mass of the bent wire?

A) 2.5 cm

B) 3.5 cm

C) 5.0 cm

D) 7.1 cm

Answer: B

13) How long does it take a wheel that is rotating at
33.3 rpm to speed up to 78.0 rpm if it has an angular acceleration of 2.15 rad/
s to power of (exponent)?

A) 20.8 s

B) 10.4 s

C) 2.18 s

D) 5.20 s

Answer: C

14) A Ferris wheel with a radius of 12.0 m rotates at a constant rate, completing
one revolution in 30.0 s. What is the apparent weight of a 60.0-kg passenger
when she is at the top of the wheel?

A) 589 N

B) 557 N

C) 615 N

D) 325 N

Answer: B

15) A dumbbell-shaped object is composed by two equal
masses, *m*, connected by a rod of negligible mass and length *r.
*If *I*_{1} is the moment of inertia of this object with
respect to an axis passing through the center of the rod and perpendicular to
it and *I*_{2} is the moment of inertia with respect to an axis
passing through one of the masses we can say that

A) *I*_{1}* = I*_{2}

B) *I*_{1}* > I*_{2}

C) *I*_{1}* < I*_{2}

D) There is no way to
compare *I*_{1}* *and*
I*_{2}*.*

Answer: C

16) A solid disk, a hoop, and a solid sphere are released
at the same time at the top of an inclined plane. They all roll without
slipping. In what order do they reach the bottom?

A) disk, hoop, sphere

B) sphere, disk, hoop

C) hoop, sphere, disk

D) hoop, disk, sphere

Answer: B

17) The rotating systems shown in the figure differ only
in that the two identical movable masses are positioned a distance *r*
from the axis of rotation (left), or a distance *r*/2 from the axis of
rotation (right). If you release the hanging blocks simultaneously from
rest,

A) the block at left lands
first.

B) the block at right lands
first.

C) both blocks land at the
same time.

D) it is impossible to tell
which block reaches the bottom first.

Answer: B

18) A 3.00-m-long ladder, weighing 200 N, rests against a
smooth vertical wall with its base on a horizontal rough floor, a distance of
1.20 m away from the wall. If the
center of mass of the ladder is 1.40 m
from its base, what frictional force must the floor exert on the base of the
ladder in order for the ladder to be in static equilibrium?

A) 93.3 N

B) 130 N

C) 40.7 N

D) 102 N

Answer: C

19) A puck moves on a horizontal air table. It is
attached to a string that passes through a hole in the center of the table. As
the puck rotates about the hole, the string is pulled downward very slowly and
shortens the radius of rotation, so the puck gradually spirals in towards the
center. By what factor will the puck's angular speed have changed when the
string's length has decreased by 1/2?

A) 2

B) 4

C) sqrt(2)

D) 1

Answer: B

**Figure 11-6**

20) The L-shaped object shown in Figure 11-6 consists of
the masses connected by light rods. How much work must be done to accelerate
the object from rest to an angular speed of 3.25 rad/s about the *y*-axis?

A) 374 J

B) 173 J

C) 42.2 J

D) 27.4 J

Answer: B