Study Guide for The Notion of Motion
- What's the First Law of Motion? Give an example.
- What's the Second Law of Motion? Give an example.
- What's the Third Law of Motion? Give an example.
- Which two Laws of Motion are in effect when the space shuttle
takes off? Discuss.
- What is a force?
- Which Law of Motion is in effect for each of the following:
- the Pioneer Space Craft speeding past Mars.
- a wrecking ball hitting a building.
- a person pulling on a boat oar.
- a car going around a banked turn.
- Why does a snow plow work better when it's full of sand?
- If you're driving with your mom and she hits the breaks suddenly
will you be thrown forward or pushed backward into your seat? If you
were holding a helium balloon at the time which direction would the
balloon go? Why? Now go home and ask your mom to buy you a helium
balloon and try it (tell her it's for science).
- Who would be harder to push on a tire swing, Skinny Scotty or Fat
- Which would drive a nail deeper into a piece of wood, a heavy
hammer or a light hammer?
- Cindy is standing in a canoe at the end of the dock but she has
forgotten to tie the canoe up. Cindy starts to walk in the canoe.
What will happen to the canoe? Which Law does this demonstrate?
- You start pushing your shopping cart toward the cookies, your mom
pushes from the other end of the shopping cart with an equal force but
she is pushing the cart toward the vegetables in the opposite
direction. Where will the cart go? Why?
- Your little red wagon is full of rocks, your sister's little red
wagon is full of feathers, you tie them together with a bungee cord,
pull them apart and let go. What will happen to the wagons? Who's
wagon will go faster? How mad will your mom be when she sees what
you've done to your and your sister's wagon?
- Which has more inertia, your Father in front of the TV during the Super bowl or you in your bed on Monday morning?
- 1st Law of Motion: An object at rest will stay at rest and an
object in motion will stay in motion (until an outside force acts upon
it). INERTIA. An example would be the rolling
bowling ball on the stage, it stops when it hits Dr. Quark or the wall
otherwise it would stay in motion. The ball at rest would stay at
rest until someone pushes it acting as an outside force to put it in
- 2nd Law of Motion: If a force acts on an object, the object will
accelerate in the direction of the force, How much depends on the size
of the force. F= ma (Force = mass x acceleration). An
example would be if you were to put a trash can at the end of your
drive way and roll a bowling ball at it. Then using the same speed
try rolling a basketball at the trash can. The bowling ball will push
the trash can more than the basketball because even though they rolled
at the same speed the mass of the bowling ball was greater than the
mass of the basketball, therefore the force generated by the bowling
ball was greater than the force generated by the basketball. Now
imagine that you are driving your mom's car. You push the gas peddle
down 1/4 of the way and you will feel pushed back into your seat.
Then you try it again but this time you push the peddle down 3/4 of
the way, you still have the same amount of mass but because the car
has more acceleration the force pushing you back into your seat is
- 3rd Law of Motion: For every action there is an equal
action in the opposite direction. Action & Reaction.
An example of this would be watching a hunter fire his rifle. When
the bullet is discharged out of the barrel of the gun, the gun will
'kick' or push backward into the hunters shoulder. The reason the gun
doesn't go as far as the bullet is because the gun has a far greater
mass than the mass of the bullet.
- The answer is primarily the 2nd & 3rd although all 3 laws are
always in effect. The gas is being discharge making as action for
which the reaction is the space shuttle going up into space (3rd). At
the same time the expulsion of gas generates a great force which
accelerates the mass of the rocket into space (2nd).
- FORCE is a push or a pull.
- Law #1, INERTIA, there is very little friction in space so an
object in motion will stay in motion.
- Law #2, F= ma, there is a big force (wrecking ball) hitting a
building which sends the building in the direction of the force.
- Law #3 Action & Reaction, you pull one way and the boat goes the
- Law # 1, INERTIA, the car wants to keep going straight, the banked
turn helps the car get around the corner.
- Because of the 2nd Law of Motion, the truck exerts more force on
the snow and moves it more easily because it has more mass.
- You would be pushed forward against your seat belt. The helium
balloon would go backward while you went forward because while you had
more mass than the air in the car the helium balloon has less mass
than the air in the car .
- Fat Albert would be harder to push than Skinny Scotty because of
Law # 1, INERTIA. Fat Albert has more mass and therefore more INERTIA
to stay at rest than Skinny Scotty.
- The heavy hammer would drive the nail further than the light
hammer because of Law # 2, F = ma. The heavy hammer has more mass and
therefore more force against the nail than the light hammer.
- As Cindy walks toward the dock the canoe will be pushed back away
from the dock. The effect being that Cindy will remain the same
distance from the dock. This demonstrates Law # 3 Action & Reaction.
The action is Cindy walking forward, the reaction is the canoe going
- The shopping cart will stay in the same spot because of Law # 3.
Your action is being countered by an equal reaction of your mothers
and the cart goes nowhere. You don't get the cookies but look at the
bright side, your mom doesn't make it to the broccoli either.
- The wagons will be pulled back together by the bungee cord. The
wagon of feathers will be pulled faster than the wagon of rocks
because it has less INERTIA to stay where it was.
- Whichever has more mass has more INERTIA to remain at rest. If
your father weighs more than you do he has more INERTIA in front of
the TV, if you weigh more than your father than you have more INERTIA
in bed on Monday.
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