Home

 

 

Momentum

http://www.thehushsound.com/

[ Flash ]

 

 

 

 

"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 a moving object that makes it difficult to stop.

(technically, product of mass and velocity)

 

 

 

Momentum = Mass x Velocity

p = mv

(kgm/s)  (kg)(m/s)

 

 

a) vector quantity

 

b) p has same direction as velocity

 

c) units - kgm/s

 

 

 

 

Momentum helps us
understand collisions

 

[Flash]

Kinetic Energy is conserved in perfectly elastic collisions

Perfectly
Elastic Collision?

 

 

 

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

 

 

 

 

 

 

Fnet = ma

 

so ...

 

Fnet = m Δv
  t

 

 

(Cross Multiply)

 

Fnett = mΔv

 

Since ...

Δp = mΔv

 

Then ...

Fnett = Δp

 

 

Force is the time rate
of change in momentum

 

Fnet = Δp
t


Δp = Ft

Force F, 'Follow through', t

 

 

 

 

Soccer ball kick.wmv

Dr. Dave's Hall of Fame

 

 

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

slapshot

Noble and Greenough School H.S.

 

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

 

 

 

 

   

"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 = Fnett
(Ns) or (kg•m/s)
 

 

 

Combining all the equations

 

* J = Fnett = mΔv =Δp *

 

Write on your test immediately
before answering questions

Given this equation, what is another unit for momentum besides kgm/s?

* J = Fnett = mΔv =Δp *

 

 

Ns

 

 

Momentum
 Word Problems

 

©Tony Mangiacapre., - All Rights Reserved [Home]
Established 1995
Use any material on this site (w/ attribution)