Physics Quiz 9

 Newton’s 3rd Law

Every action has an equal and opposite reaction.

How does the magnitude (size of the force) between two colliding objects compare when the objects have different mass or are moving at different speeds? Make sure to consider both magnitude and direction.

__Equal__ in magnitude opposite direction

What FOUR things must be true for a pair of forces to be an action-reaction pair?
Provide an example of an action-reaction pair.

1. Same type of force
2. Between same two objects
3. Force is equal in magnitude (the amount)
4. Opposite in direction

Understand what Newton’s 3rd Law tell us about the impulse (change in momentum) of objects that interact.

The impulse (change in momentum) is equal but in the opposite direction.

How does the change in momentum of two colliding objects compare when the objects have different mass or are moving at different speeds? Make sure to consider both magnitude and direction.

__Equal__, With different mass and speed they have the same change in momentum but in the opposite direction. 

ΔP=Ft

What do we know about the total momentum of a system when there is a collision or explosion? (review the collisions investigation)

They are always the same but in different directions so it equals zero.

You hit a nail with a heavy hammer.
Which object (hammer or nail) experiences a greater impact force when they collide? Why?

They have equal magnitude of force

F=mv

You hit a nail with a heavy hammer.

Which object experiences a greater change in momentum? Why?

They have the same change in momentum
Ft=ΔP

You hit a nail with a heavy hammer.

Which object accelerates more during impact? Why?

The smaller one (nail) because it has less inertia

a=F/m