Chapter 7 Study Guide

Name______Date of Test______#____

Fill in the blanks with the correct answers.

1.What happens when two forces act in the same directions? ______

2. The force that one surface exerts on another when the two rub against each other is called ______

3. Forces can be added together only if they are acting on the ______object.

4. The property of matter that resists a change in motion is called ______

5. The overall force on an object after the forces are added together is called a

______force

6. The greater the mass of an object, the ______its inertia.

7. The force of gravity between you and Earth is greater than the force of gravity between you and a car because Earth has more ______than the car.

8. Friction depends on the types of surfaces involved and how ______the surfaces push together.

9.Mass and ______affect the gravitational attraction between objects.

10.The following pairs of surfaces are pushed together with the same amount of force. Between which pair of surfaces will friction be the greatest?

Circle your answer.

2 pieces of sandpaper 2 pieces of wax paper

a painted surface and a piece of sandpaper

11.The force of gravity on a person or object on the surface of a planet is called ______

12.The law of universal gravitation states that any two objects in the universe that have mass, without exception, ______each other.

13.What type of friction acts between objects that are not moving? ______

14.According to Newton’s ______law of motion, if you kick a soccer ball with your bare foot, it hurts because the ball exerts a force on your foot equal in size to the force you exert on the ball.

15.According to Newton’s third law of motion, the strength of a reaction force is ______the strength of the action force.

16.One ______is the force required to accelerate 1 kilogram of mass at 1 meter per second per second.

17.Friction always acts in the ______direction as the direction of motion.

18.According to Newton’s 2nd law of motion, ______depends of an object’s mass and net force acting on the object.

19.According to Newton’s third law of motion, when a hammer strikes and exerts force on a nail, the nail exerts an ______and ______force on the hammer.

20.A force is described by its ______and ______

Answer in complete sentences.

21. A book is sitting on the dashboard of a car that is stopped at a traffic light. As the car starts to move forward, the book slides backward off the dashboard. Use the term INERTIA to explain what happened.

22. A skydiver with a mass of 70kg accelerated to Earth at a rate of 10.8 m/s due to gravity. What is the force on the skydiver? Explain how you determined the answer and its units.

23. If you drop your pencil, you observe the pencil fall and accelerate toward Earth due to the force of gravity. Explain why you don’t observe Earth accelerate toward the pencil, even though the pencil pulls on Earth with an equal and opposite reaction force.