Name:    Forces Quiz

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

1.

If you increase the force on a box, it will have
 A. greater inertia. B. less inertia. C. greater acceleration. D. less acceleration.

2.

The strength of the gravitational force between objects depends on
 A. mass and distance. B. pressure and area. C. mass and volume. D. force and acceleration.

3.

When one object exerts a force on another object, the second object exerts a force back on the first object that is
 A. equal in size and opposite in direction. B. equal in size and in the same direction. C. unequal in size and opposite in direction. D. unequal in size and in the same direction.

4.

Balanced forces act on
 A. two different objects. B. the same object. C. balanced objects. D. unbalanced objects.

5.

Centripetal force keeps an object moving in a circle. This force points
 A. toward the center of the circle. B. toward the outer edge of the circle. C. to the right of the center of the circle. D. away from the circle in all directions.

6.

If a 50 kg racer in a 25 kg soapbox car is pushed with a force of 150 N, what will be the racer’s acceleration?
 A. 2 m/s/s C. 6 m/s/s B. 3 m/s/s D. 11,250 m/s/s

7.

You sit down in a chair to watch your favorite television show. The action force is your weight pushing down on the chair. What is the reaction force?
 A. air pressing on your body from all sides. B. the chair pushing up on your body. C. the muscles of your legs pushing against the legs of the chair. D. the back of the chair supporting your back.

8.

A push or pull is called
 A. motion. B. force. C. acceleration. D. velocity.

9.

You push two chairs in a straight line with the same force. One chair is more massive than the other. The more massive chair will have
 A. greater acceleration. B. less acceleration. C. greater centripetal force. D. less centripetal force.

10.

Janet is sliding a box across the floor. What does she need to know to calculate the force on the box?
 A. mass and inertia B. acceleration and friction C. mass and acceleration D. friction and gravity

11.

Inertia is the resistance of an object to a change in its
 A. gravity B. motion C. mass D. balanced force

12.

Action/reaction force pairs act on
 A. two different objects. B. the same object. C. balanced objects. D. unbalanced objects.

13.

A soccer player kicks a ball that is at rest. What do you predict will happen?
 A. The ball will not move. B. The ball will lose momentum. C. The ball will accelerate in the direction opposite the applied force. D. The ball will accelerate in the same direction as the applied force.

14.

Kelly slides a box from a carpeted floor onto a tile floor. The force she is applying does not change. What do you predict will happen?
 A. The box will speed up because the amount of friction decreases. B. The box will continue moving at the same rate because the amount of friction remains the same. C. The box will slow down because the amount of friction increases. D. The box will stop moving because Kelly's force will not be enough to overcome friction.

15.

When you push on a door, the door pushes back with an equal and opposite force. These two forces are known as
 A. mass and velocity force pairs B. unbalanced force pairs C. mass and acceleration force pairs D. action/reaction force pairs

16.

Which of the following is an example of zero net force applied to an object?
 A. a skier moving down a mountain with increasing speed B. a car turning left without changing speed C. a ball being hit into the outfield with a bat D. a rope pulled equally from opposite ends

17.

If one force is balanced by another force, the
 A. effect is the same as no force at all. B. effect is a positive net force. C. size of the first force is balanced by the direction of the second force. D. direction of the first force is balanced by the size of the second force.

18.

A boy pushes a shopping cart with a force of 10 N, and the cart accelerates 2 m/s/s.  What is the mass of the cart?
 A. 0.2 kg B. 2.5 kg C. 5 kg D. 20 kg

19.

Newton's first law describes the tendency of objects to resist a change in motion. This resistance is also called
 A. inertia. B. net force. C. friction. D. gravity.

20.

One way to decrease acceleration is to
 A. decrease force and mass equally. B. increase force more than mass. C. increase mass. D. decrease mass.

21.

Sebastian lifts his book off the floor.  Which of the following vector arrow combinations best represent the forces acting on the book?
 A. B. C. D. 22.

What units are used to measure force?
 A. kilograms B. meters/s/s C. seconds D. newtons

23.

The force that attracts two masses to each other is called
 A. air resistance. B. friction. C. gravity. D. pressure.

24.

A girl pulls a wheeled backpack with a force of 3 N.  If the backpack has a mass of 6 kg, what is its acceleration?
 A. 0.5 m/s/s B. 2 m/s/s C. 18 m/s/s D. 20 m/s/s

25.

A hollow plastic ball and a solid metal ball are dropped from the same height in a vacuum. With no air resistance, gravity is the only force acting on the balls. What do you predict will happen?
 A. The balls will fall at the same rate. B. The metal ball will fall faster. C. The plastic ball will fall faster. D. The larger ball will fall faster.

26.

James combines all the forces acting on a tennis ball. He is finding the
 A. net force. B. inertia force. C. gravitational force. D. frictional force.

27.

A skater is moving at a constant speed. How can he increase his speed?
 A. drag the heel stop to increase friction B. lean to one side, causing the skates to turn C. reduce the force with which he pushes his feet against the ground D. increase the force with which he pushes his feet against the ground

28.

Roger is designing a new model rocket. He wants it to have as little air resistance as possible. What should he do?
 A. decrease its surface area B. lower its temperature C. increase its speed D. make its surface rougher

29.

How much force is needed to accelerate a 0.149 kg baseball 3 m/s/s?
 A. 0.049 N B. 0.447 N C. 14.930 N D. 20.134 N

30.

What is the net force of the object represented by the free body diagram below? A. 0 N B. 15 N to the right C. 20 N downward D. 25 N to the left