Rotational Motion
Practice Test
1.
In Figure 7-5, if the mass of the Sun were doubled, what effect would it have on the planet's period of orbit?
a.
The new period would be one-half of the original period.
b.
The new period would be twice the original period.
c.
It would have no effect.
d.
The new period would be one divided by the square root of two times the original period.
Hint
2.
In Figure 8-3, why does applying a force as in the picture at the bottom left result in no effect?
a.
The force is applied perpendicular to the lever arm.
b.
The force is applied parallel to the lever arm.
c.
The force is applied perpendicular to the axis of rotation.
d.
The force is applied at the axis of rotation.
Hint
3.
What causes the Coriolis force?
a.
low pressure areas
b.
winds
c.
the rotation of Earth
d.
gravity
Hint
4.
Which of the following situations is physically the most like that depicted in Figure 6-9a?
a.
You step upwards on an upward-moving escalator.
b.
You slide to the right on the seat of a forward-moving bus.
c.
You walk toward the rear of a forward-moving train.
d.
You jump up in an elevator that is going down.
Hint
5.
Two bowling balls each have a mass of 6.3 kg. They are located next to each other with their centers 16.5 cm apart. What gravitational force do they exert on each other? Assume
G
= 6.67×10
-11
N·m
2
/kg
2
.
a.
1.6×10
-8
N
b.
3.1×10
-7
N
c.
9.7×10
-8
N
d.
9.7×10
-8
N/m
2
Hint
6.
In Figure 8-2, if the radius of the CD is 6.0 cm and the angular velocity is 5.0 rad/s, what is the linear displacement of a point on the edge in 2.0 s?
a.
3.8 m
b.
0.60 m
c.
60 m
d.
0.30 m
Hint
7.
A 225-N weight has one horizontal rope exerting a force of 98.0 N on it. What are the magnitude and direction of the force needed to put the weight into equilibrium?
a.
2.45×10
2
N at 293°
b.
2.45×10
2
N at 113°
c.
1.27×10
2
N at 113°
d.
2.45×10
1
N at 113°
Hint
8.
The acceleration of an object in uniform circular motion is called __________.
a.
equilibrium
b.
torque
c.
centripetal acceleration
d.
range
Hint
9.
A force that produces equilibrium is a(n) __________.
a.
equilibrant
b.
net force
c.
constant
d.
resultant
Hint
10.
The product of the force and the lever arm is called __________.
a.
power
b.
range
c.
torque
d.
equilibrium
Hint
11.
You are riding in a boat that is traveling 15.0 m/s in still water. You move from the bow to the stern at 3.0 m/s. What is your speed relative to the water?
a.
9.0 m/s relative to the water
b.
12.0 m/s relative to the water
c.
15.3 m/s relative to the water
d.
18.0 m/s relative to the water
Hint
12.
You accidentally throw your car keys horizontally at 5.0 m/s from a cliff 45 m high. How far from the base of the cliff should you look for your keys?
a.
225 m
b.
45 m
c.
15 m
d.
135 m
Hint
13.
When there is no relative motion between two surfaces, the force exerted by one surface on the other is called __________.
a.
the kinetic force
b.
the static friction force
c.
kinetic friction
d.
resistance
Hint
14.
A projectile's path through space is called its __________.
a.
flight plan
b.
period
c.
trajectory
d.
range
Hint
15.
The __________ of an object is the point on the object that moves in the same way that a point particle would move.
a.
center of mass
b.
axis
c.
orbit
d.
torque
Hint
16.
A mass that rotates around its own axis is a(n) __________.
a.
orbiter
b.
satellite
c.
projectile
d.
rigid rotating object
Hint
17.
The __________ of an object is measured by applying a force to the object and measuring its acceleration.
a.
resistance
b.
inertial mass
c.
weight
d.
gravitational mass
Hint
18.
If you weigh 440.0 N on Earth's surface, how much would you weigh on the planet Mars? Mars has a mass of 6.42×10
23
kg and a radius of 3.40×10
6
m.
a.
557 N
b.
1.4×10
3
N
c.
165 N
d.
235 N
Hint
19.
In Figure 6-7, if the mass of the hammer is 7.26 kg, its center is 0.50 m from the thrower, and it is moving at a speed of 1.5 m/s, what is the tension in the chain?
a.
22 N
b.
33 N
c.
3.0 N
d.
4.5 N
Hint
20.
A sled of mass 40.0 kg is pulled along flat, snow-covered ground. The static friction coefficient is 0.28, and the kinetic friction coefficient is 0.08. What force will be needed to start the sled moving?
a.
392 N
b.
147 N
c.
31 N
d.
110 N
Hint
