Momentum

1
Momentum Impulse

• Think of P as in
• Pmomentum

2
Momentum Impulse

• Momentum m x v, its a vector, P m x v
• Remember F ? P/ ? time m ?v/?t ma
• Impulse is defined as F?t Force x time.
• F?t m?v, this is the impulse momentum theorem,
  an impulse causes a change in momentum (big deal)

3
Momentum and Impulse

• F?t m?v
• This is often used when youre trying to find the
  average force during a short interval of time,
  you can use the change in momentum. For example,
  like hitting a golf ball, the force happens over
  a short time and its very non-linear, but you
  can determine the average force if you know the
  change in momentum.

4
Conservation of momentum

• For Momentum Conservation, This rule works for
  2 objects colliding or interacting.
• ?(mv)before ?(mv)after
• Typically 3 cases
• A moving object runs into a stationary object.
• Objects explode away from each other, both
  starting at rest
• Both objects moving , then colliding

5
Elastic and Inelastic Collisions

• In a pure Elastic collisions, 2 objects bounce
  off each other and Kinetic Energy is conserved,
  meaning the total KE before total KE after (KE
  ½ mv2).
• Inelastic collisions, objects stick together, KE
  is not conserved.
• In either case, can still use conservation of
  Momentum to determine velocities.