Force Packet Answer Key: Pages 1-4
Page 1:
Gravity:
1) The force of gravity increases
2) Mass is the amount of matter in an object. weight is the force of gravity on an object at the surface of a planet. ( The
amount that gravity pulls on your mass, is how much you weigh)
3) You weigh less on the moon because the moon has less gravity
(Mass does not change, but your weight changes because there is less gravitational force pulling down on your mass on
the moon)
Friction and Unbalanced forces:
1) No (the forces are balanced)
2) Static, (sliding after it starts to moving or if it was moving)
3) 0 N (balanced forces)
4 )Apply enough (additional) force to break static friction and cause the object to slide
Page 2:
These were your own interpretations of the four types of friction, With included drawings. They should include the
following but are not limited to these answers because it should be your own definition:
Static: it not moving or keeps objects from moving or slipping
Sliding: Occurs when solid surfaces slide over another
Rolling: Occurs when an object rolls over a surface
Fluid: Acts on a solid object when if moves through a fluid ( example: air and liquid)
Page 3: The Law of Gravity: Read the passages
1) The objects' mass and the distance between the two objects
2) Mass is the amount of matter in a n object
3) Mass is the amount of matter in an object. An objects mass does not change because of the objects location. Weight
is the measure of the gravitational pull acting on an objects mass. An objects weight depends on its mass as well as its
location
4) About 250 pounds
5. False
6. True
7. True
8. False
Page 4: Review and Reinforce: The nature of force
1) Write the phrases listed on the Venn Diagram
Unbalanced forces
Net force not equal zero
Change in objects motion
Have direction
Shared Characteristics
Balanced Forces
and unbalanced forced
Push or Pull
Balanced forces
-Net force = 0
-Do not change an objects motion
2) when an objects is moving it will keep moving until it hits something or something stops it, like a ball kicked
out into a field.
-Something that is not moving will keep still until something moves it. Like cloths on your bedroom floor.
3. C
4. A
5. D
6. E
7. F
8. B
Page 5: Newton's Big 3
1) 4500 N
2) 150-kg sumo wrestler, because he has more mass
3)The birds wings apply an action force on the air and the air applies a reaction force on the birds wings.
pg 6: Extra Credit
pg7: Force and Acceleration:
1) 6000N 2) 30N
3) 14.7kg
4) 50 m/s² 5) 800 N
pg 8: Force Mass, and acceleration:
1) Force= (mass) x (acceleration)
2) C
3) A
4) D
5) C
6) A
7) The strength of force
8) m/s²
Page 9: Which law is it?
1) Newton's 3rd Law
2) Newton's 1st law
3) 2nd law because of the change in mass, need to increase the force to accelerate a bowling ball with a
baseball bat
4) 3rd law
5) 3rd law
6) 1st law--Inertia
7) 1st Law
8) 2nd
9) 1st
10) 2nd
Page 10: Newton's Notions:
1) You are in motion with the car, but when the brakes are applied on the car, the brakes stop the car, not
you. Due to inertia (the tendency for objects to resist a change in motion, or to keep moving) your body is an
object in motion that wants to stay in motion- and will stay in motion until an unbalanced force acts upon it.
The seat belt, is an unbalanced force that restrains you and keeps you in your seat , preventing you from your
continued motion..
2) When forces act... bumping into you slowing you down.
3) According to Newton's 3rd Law, every action has an equal and opposite reaction. As the diver dives forward
off the boat, the boat will respond by moving backwards. This is because as the diver applies a downward
force pushing off the boat, the boat is applying a push (force) upward on her.
4) Friction is the force that opposes motion and acts in the opposite direction of motion. This opposite force
helps slows the object down while rolling and may even eventually stop the motion.