Name:    Chapter 4 Pre-Test

Multiple Choice
Identify the choice that best completes the statement or answers the question.

1.

Accelerations are produced by
 a. forces. b. velocities. c. accelerations. d. masses. e. none of the above

2.

How does acceleration of an object change in relation to its mass? It is
 a. directly proportional. b. Acceleration doesn't depend on mass at all. c. inversely proportional.

3.

When an object reaches terminal velocity its acceleration is
 a. 0 m/s2. b. 4.9 m/s2. c. 9.8 m/s2.

4.

A heavy person and a light person parachute together and wear the same size parachutes. Assuming they open their parachutes at the same time, which person reaches the ground first?
 a. the light person b. the heavy person c. Neither -- they both reach the ground together.

5.

A 10-kg brick and a 1-kg book are dropped in a vacuum. The force of gravity on the 10-kg brick is
 a. 10 times as much as the force on the 1-kg book. b. zero. c. the same as the force on the 1-kg book.

6.

When a woman stands with two feet on a scale, the scale reads 280 N. When she lifts one foot, the scale reads
 a. less than 280 N. b. more than 280 N. c. 280 N.

7.

An apple weighs 1 N. The net force on the apple when it is in free fall is
 a. 0 N. b. 0.1 N. c. 1 N. d. 9.8 N. e. none of the above

8.

A force of 3 N accelerates a mass of 3 kg at the rate of 1 m/s2. The acceleration of a mass of 6 kg acted upon by a force of 6 N is
 a. twice as much. b. half as much. c. the same. d. none of the above

9.

If you pull horizontally on a desk with a force of 150 N and the desk doesn't move, the friction force must be 150 N. Now if you pull with 250 N so the desk slides at constant velocity, the friction force is
 a. more than 150 N but less than 250 N. b. 250 N. c. more than 250.

10.

When the angle of an incline with a block resting on it increases, the normal support force
 a. increases. b. stays the same. c. decreases.

11.

A 20-N falling object encounters 4 N of air resistance. The magnitude of the net force on the object is
 a. 0 N. b. 4 N. c. 16 N. d. 20 N. e. none of the above

12.

A tow truck exerts a force of 2000 N on a car, accelerating it at 1 m/s/s. What is the mass of the car?
 a. 667 kg b. 1000 kg c. 2000 kg d. 8000 kg e. none of the above

13.

You pull horizontally on a 50-kg crate with a force of 450 N and the friction force on the crate is 250 N. The acceleration of the crate is
 a. 2 m/s2. b. 4 m/s2. c. 9 m/s2. d. 14 m/s2.

14.

How much force is needed to accelerate a 4.0-kg physics book to an acceleration of 2.0 m/s2?
 a. 0 N b. 2.0 N c. 0.5 N d. 8.0 N e. 24.0 N

15.

A 6-N falling object encounters 6 N of air resistance. The magnitude of the net force on the object is
 a. 0 N. b. 6 N. c. 12 N. d. none of the above

True/False
Indicate whether the statement is true or false.

16.

The combination of all the forces that act on an object is called the net force.

17.

The acceleration of an object is inversely proportional to the net force acting on it.

18.

The net force on an objecting falling at terminal velocity is zero.

19.

It is possible for an object in free fall to have zero acceleration.

20.

The speed of an object dropped in air will continue to increase without limit.