Chapter 3:
Forces
Practice Test
1.
A 2 kg object is dropped from a height of 1000 m. What is the force of air resistance on the object when it reaches terminal velocity?
a.
2000 N
b.
500 N
c.
9.8 N
d.
19.6 N
Hint
2.
How fast must a 50 kg mass travel to have a momentum of 1500 kg m/s?
a.
330 m/s
b.
75,000 m/s
c.
30 m/s
d.
0.33 m/s
Hint
3.
If you are pushing on a box with a force of 20 N and there is a force of 7 N on the box due to friction, what is the net force on the box?
a.
140 N
b.
- 7 N
c.
13 N
d.
27 N
Hint
4.
What is the net force on a 4000 kg car that doubles its speed from 15 m/s to 30 m/s over 10 seconds?
a.
400 N
b.
60,000 N
c.
40,000 N
d.
6000 N
Hint
5.
A 3200 N force is applied to a 160 kg mass. What is the acceleration of the mass?
a.
512 m/s
2
b.
50 m/s
2
c.
20 m/s
2
d.
0.05 m/s
2
Hint
6.
If a 5000 kg mass is moving at a speed of 43 m/s, what is its momentum?
a.
0.0086 kg m/s
b.
215,000 kg m/s
c.
116 kg m/s
d.
49,000 N
Hint
7.
How much force is needed to lift a 25 kg mass?
a.
15.2 N
b.
0.392 N
c.
0.255 N
d.
245 N
Hint
8.
A 85 kg mass has an acceleration of 5.5 m/s
2
. What is the force applied?
a.
467.5 N
b.
1.54 N
c.
0.06 N
d.
15.4 N
Hint
9.
The acceleration due to gravity on the moon is about 1.6 m/s
2
. If you weigh 700 N on Earth, how much would you weigh on the moon?
a.
6860 N
b.
114 N
c.
1120 N
d.
428 N
Hint
10.
A person is on an elevator that moves downward with an acceleration of 1.8 m/s
2
. If the person weighs 686 N, what is the net force on the person?
a.
1234.8 N
b.
381.1 N
c.
126 N
d.
686 N
Hint
