Download Unit 2 Worksheet – Motion and Forces Do Not Write on this Paper

Unit 2 Ch 12 Worksheet –Forces Do Not Write on this Paper. Put all
answers on a separate sheet of notebook paper.
Forces
1. When the forces acting on an object are ____, the net force is zero.
2. An object in motion at a constant velocity will change its motion only if a
___ force acts on it.
In a car crash, ___could cause you to crash into the windshield.
The combination of all of the forces acting on an object is called the _
If the net force acting on a stationary object is zero, then the object will ___
A tug-of-war that results in one team pulling the other across the line is an
example of ___ forces
7. Which of the following best illustrates balanced forces?
a) a rock falling to the ground b) a stretched rubber band being held
between two hands c) a person lifting a heavy box off of the ground
d) a crash between a large truck and a train
8. Friction is defined as ___
9. Weight is best described as ___
10. When objects are moved further apart from each other, the force of
3.
4.
5.
6.
gravity (increases / decreases)
11. Of the following, the greatest gravitational force would occur
between: a) a marble and a baseball 5 meters apart. b) a loaded
freighter on the high seas and Earth. c) the moon and an astronaut
standing on the moon d) the moon and Earth.
12. The law that states that every object maintains constant velocity
unless acted on by an unbalanced force is ___.
13. The law that states that for every action force there is an equal and
opposite reaction force is ___
14. The law that states that the unbalanced force acting on an object equals the
object’s mass times its acceleration is ___
15. The SI unit of force, named for the scientist who described the relationship
between motion and force, is called the ___
16. What is the constant for acceleration in free fall on Earth?
17. Write all of the following statements that are true?
a) Weight and mass are proportional but not equal b) Weight is the
gravitational force an object experiences due to its mass. c) The
weight of an object on Earth is greater than the weight of the same
object on the surface of the moon, but the object's mass stays the
same d) weight and mass are always the same.
18. When air resistance balances the weight of an object that is falling, the
velocity ____
19. Inertia varies depending on ____.
20. Newton's first law of motion is also called the law of ____.
21. According to Newton’s second law of motion, force is the product of ____
and _____
22. If the forces acting on an object at rest are ___, the object will remain at rest
23. At the same speed, a bowling ball is harder to stop than a soccer ball
because the bowling ball has greater _____
24. If two vehicles collide, name at least one outside force that will come into
effect immediately after the impact and cause the objects to eventually come
to a stop.
25. You are pushing a heavy crate across a cement floor when you hit a section
of flooring covered with smooth steel plates. Suddenly it is somewhat easier
to push the crate. Why?
26. Rearrange the equation for Newton’s second law of motion to define
acceleration in terms of force and mass.
27. Why does it require less fuel to accelerate a rocket in outer space than in
Earth’s atmosphere?
28. If you are running and you stub your toe, you fall forward. Explain.
29. Why is it necessary to wear a seat belt to hold you in place if you are riding
in a car that stops suddenly?
30. The ___ velocity is the highest velocity that will be reached by a falling
object
31. The upward force on an object falling through the air is ____.
32. In the absence of air, a penny and a feather that are dropped from the same
height at the same time will ____.
33. The size of the gravitational force between two objects depends on their __.
34. The statement "to every action there is an equal and opposite reaction" is __.
35. A 300-N force acts on a 25-kg object. The acceleration of the object is ____.
36. A 3,000-N force acts on a 200-kg object. The acceleration of the object is__.
37. Action-reaction forces always act on ___ objects
38. Sally sits on a rock. Her weight is an action force. Describe its reaction
force
39. Why is your weight less on the Moon than on Earth, but your mass is the
same?
40. Calculate the force on an object that has a mass of 12 kg and an acceleration
of 4 m/s2.