Gravitation
Practice Test
1.
The force exerted by a spring scale is called __________.
a.
the apparent weight
b.
the kinetic force
c.
terminal velocity
d.
kinetic friction
Hint
2.
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.
12.0 m/s relative to the water
b.
18.0 m/s relative to the water
c.
15.3 m/s relative to the water
d.
9.0 m/s relative to the water
Hint
3.
Any moving object that moves through the air only under the force of gravity (after initial thrust) is a(n) __________.
a.
free floater
b.
vector
c.
satellite
d.
projectile
Hint
4.
In Figure 4-16c, if the box has a mass of 6.0 kg, what will the normal force of the table on the box be?
a.
110 N
b.
9.8 N
c.
50 N
d.
8.8 N
Hint
5.
How far does a car travel in 30.0 s while its velocity is changing from 50.0 km/h to 80.0 km/h at a uniform rate of acceleration?
a.
5.40×10
2
b.
1.08 × 10
3
m
c.
252 m
d.
1.95 × 10
3
m
Hint
6.
The specific, immediate cause of a force is called the __________.
a.
contact
b.
system
c.
agent
d.
origin
Hint
7.
A car is accelerated uniformily at the rate of 0.50 m/s
2
for 1.0×
1
s. Its final velocity is 23 m/s. What is the initial velocity?
a.
18 m/s
2
b.
28 m/s
2
c.
18 m/s
d.
28 m/s
Hint
8.
If Earth began to shrink but its mass remained the same, what would happen to the value of
g
on Earth's surface?
a.
It would decrease.
b.
It would be halved.
c.
It would increase.
d.
It would remain constant.
Hint
9.
In Figure 6-1, if the baseballs fell a vertical distance of 1.6 m from the first to the last image, what is the time interval between frames?
a.
0.23 s
b.
0.071 s
c.
0.095 s
d.
0.081 s
Hint
10.
If standing on a scale in an elevator, as in Figure 4-9, and the scale reads 120% of your weight, what is the acceleration of the elevator?
a.
0.2
g
, up
b.
0.8
g
, up
c.
1.2
g
, down
d.
0.2
g
, down
Hint
11.
A satellite orbits Earth 375 km above its surface. What is its period?
a.
1.54 h
b.
55.3 h
c.
16.0 h
d.
92.1 h
Hint
12.
Which of the following situations is physically the most like that depicted in Figure 6-9a?
a.
You slide to the right on the seat of a forward-moving bus.
b.
You jump up in an elevator that is going down.
c.
You walk toward the rear of a forward-moving train.
d.
You step upwards on an upward-moving escalator.
Hint
13.
A carnival ride has a 3.0-m radius and rotates once every 1.7 s. Find the centripetal acceleration of a rider.
a.
98 m/s
2
b.
82 m/s
2
c.
41 m/s
2
d.
11 m/s
2
Hint
14.
An object is in equilibrium when __________.
a.
its acceleration is constant
b.
the equilibrant is zero
c.
the net force on it is zero
d.
three or more forces act on it
Hint
15.
In Figure 4-16b, if the box has a mass of 6.0 kg, what will the normal force of the table on the box be?
a.
50 N
b.
8.8 N
c.
160 N
d.
9.8 N
Hint
16.
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 its centripetal acceleration?
a.
22 m/s
2
b.
33 m/s
2
c.
3.0 m/s
2
d.
4.5 m/s
2
Hint
17.
In 1798, __________ devised an apparatus to measure the gravitational force.
a.
Johannes Kepler
b.
Isaac Newton
c.
Tycho Brahe
d.
Henry Cavendish
Hint
18.
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 resultant force on the weight?
a.
1.27×10
2
N at 315°
b.
2.45×10
2
N at 293°
c.
2.45×10
1
N at 293°
d.
2.45×10
2
N at 343°
Hint
19.
A force that produces equilibrium is a(n) __________.
a.
constant
b.
net force
c.
equilibrant
d.
resultant
Hint
20.
Two 1.00-kg masses have their centers 1.00 m apart. What is the force of attraction between them?
a.
9.7×10
-8
N
b.
1.33×10
-10
N
c.
6.67×10
-11
N
d.
6.67×10
11
N
Hint
