Physical Science II
Force and Newton’s Laws Review
Name_____________________
Period ____________________
This is the review for Chapter 12: Force and Newton’s Laws. The test for this chapter is going to be on
Wednesday, November 2nd. This test will be on the First Marking Quarter!
Please write all of your answers on a separate sheet of paper, since there is not much room to write
between questions. This review will be checked for a classwork grade.
1. What is a Force?
A force is a push or a pull acting on an object.
2. What are the two types of forces?
Contact forces and field forces.
3. Write an example of a contact force.
Pulling a door closed. Pushing a refrigerator across a kitchen floor.
4. Write an example of a field force.
Gravity and Magnetism.
5. What are the units used to measure force?
Newtons (N)
6. List the four different types of friction.
Static, Kinetic, Rolling and Fluid
7. What is static friction? Write an example.
Static friction opposes the start of motion. It only acts on objects at rest. An example would
be the force acting between a carpet and a stationary sofa.
8. What is kinetic friction? Write an example.
Kinetic friction acts against the motion of moving objects. An example would be the force
acting against a box that is sliding across a floor.
9. What is rolling friction? Write an example.
Rolling friction is a force that acts against objects that are rolling. An example would be the
force acting against the wheels of roller blades.
10. What is fluid friction? Write an example.
Fluid friction is a force that opposes the motion of an object moving through a fluid (liquid or
gas). An example would be air resistance or the force of the water acting against the motion
of a swimmer.
11. What is gravity?
Gravity is an attractive force that acts between objects with mass.
12. What determines the size of a gravitational force?
Mass determines the size of an objects gravitational force.
13. What is another name for the force of gravity acting on an object?
Weight is the force of gravity acting on an object.
14. Why do a penny and a feather fall at different speeds on Earth?
The only reason a penny and a feather fall at different speeds on Earth is because of air
resistance.
15. Inside of a vacuum, which object would fall faster, a quarter or a feather?
Inside of a vacuum the feather and the penny will fall at the same speed.
16. If a ball is thrown horizontally and another is dropped straight downward at exactly the same
moment, which will hit the ground first?
Both balls would hit the ground at exactly the same time.
17. Who was the first scientist to propose an idea about why objects move?
Aristotle
18. Which scientist first disproved Aristotle’s ideas about motion?
Galileo
19. Who was the scientist that discovered the laws of motion that we use to describe the
movements of all large objects in the universe?
Isaac Newton
20. Who invented the reflecting telescope?
Isaac Newton
21. What is Newton’s 1st Law?
The law of inertia. An object at rest stays at rest and an object in motion stays in motion
unless a force acts on the object.
22. What is Newton’s 2nd Law?
F = ma or Force equals the product of the mass of an object and its acceleration.
23. What is Newton’s 3rd Law?
For every force there is an equal and opposite force.
24. Use Newton’s Laws to answer the following questions:
a. Why would a passenger fly off of a wave runner if the driver makes a sudden turn?
The passenger will try to continue moving in a straight line at the same speed
according to Newton’s 1st Law. Thus if the passenger does not hold on, they will fly off
the wave runner when it makes a turn.
b. How could you figure out the acceleration of a mass when you know the force acting on
it?
Since force equals mass times acceleration (F = ma), the acceleration would be equal
to the Force divided by the mass (a = F/m).
c. What are the action and reaction forces acting on a baseball player as he slides into
second base?
The baseball player is pushing against the ground and the ground is pushing back
against the baseball player.
25. Which one of Newton’s Laws is called the Law of Action-Reaction forces?
Newton’s 3rd Law.
26. Which one of Newton’s Laws is also known as the Law of Inertia?
Newton’s 1st Law
27. If a football is being pulled to the ground by the Earth, the Earth is being pulled by the football
with an equal amount of force. Why don’t we see the Earth move upwards toward the football?
We don’t notice the motion of the Earth because its mass is so enormous. The large mass of
the Earth causes it to have almost no acceleration.
28. How much force would it take to accelerate a 2500-kg car at a rate of 10-m/s2?
F = ma
F = (2500-kg)(10-m/s2)
F = 25,000-N
29. What would be the acceleration of a 6-kg cat that exerts a force of 42-N with its back legs?
a = F/m
a = 42-N / 6-kg
a = 7-m/s2
30. What would be the force acting on a 50-kg chair that is being pushed with an acceleration of
2.5-m/s2?
F = ma
F = (50-kg)(2.5-m/s2)
F = 125-N
31. What is the mass of a weasel that accelerates at 3.5-m/s2 using a force of 15-N?
F = ma
m = F/a
m = (15-N) / (3.5-m/s2) m = 4.29-kg
32. What is the weight of a 45-kg person?
W = mg
W = (45-kg)(9.8-m/s2)
W = 441-N
33. What is the mass of a person who weighs 620-N?
W = mg
m = W/g
m = (620-N) / (9.8-m/s2)
m = 63.27-kg