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Review of the 3 Laws of Motion

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"Which is tougher to stop, a bowling ball or  a baseball?"

It Depends ....       If the baseball had a much larger velocity, it  would be harder to stop.

I. Momentum - the property of moving object has that makes it difficult to stop.

(technically, product of mass and velocity)

Momentum = Mass x Velocity

p = mv

(kg•m/s)  (kg)(m/s)

a) vector quantity

b) p has same direction as velocity

c) units - kg•m/s

Momentum helps us understand  elastic collisions

No

The ball's energy is lost in the collision with the floor. It does not return its original position.

"Could a moving baseball have the same momentum as moving bowling ball?"

"Yes. p = mv. The baseball's velocity would have to be many  times faster."

1) Relationship between force and momentum

When a force acts on a body it
 changes its' momentum.

Mathematical Relationship, F, p

p = mv

so ...

Δp = mΔv

F = ma

so ...

(Cross Multiply)

Ft = mΔv

Since ...

Δp = mΔv

Then ...

Ft = Δp

Force is the time rate
of change in momentum

Δp = Ft

Force F, 'Follow through', t

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The change in momentum that an unbalanced force produces on an object depends on ....

Noble and Greenough School H.S.

... how long the force acts on a body.

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	"Could a female golfer EVER change the momentum of a golf ball more than a male golfer?"

Yes. She can compensate for a smaller force
by employing a good 'follow through'

2)  Impulse 

J = Ft

(Ns) or (kg•m/s)

Combining all the equations

Write on your test immediately
before answering questions