Momentum

1
Momentum

• Inertia in Motion

2
What is momentum?

• Momentum is a commonly used term in sports. A
  team that has the momentum is on the move and is
  going to take some effort to stop.
• A team that has a lot of momentum is really on
  the move and is going to be hard to stop.
• The sports announcer says "Going into the
  all-star break, the Chicago Cubs have the
  momentum."
• Coach Havlik pumps up his team at half-time,
  saying "You have the momentum the critical need
  is that you use that momentum and bury them in
  this third quarter."

3
What is momentum?

• Momentum is a physics term it refers to the
  quantity of motion that an object has. A sports
  team which is on the move has the momentum. If an
  object is in motion (on the move) then it has
  momentum.
• The quantity of motion arising from velocity
  and the quantity of matter conjointly.
• Isaac Newton
• Any object which has both
• mass and a velocity is said
• to have momentum.
• Inertia in motion

4
Components of Momentum

• Momentum mass velocity
• p m x v
• Units kg m/s
• Therefore, massive objects moving at a high speed
  have a large momentum

5
Two cases of Momentum

• A slow moving elephant has a large momentum.
• Even though it has a small velocity, it has a lot
  of mass
• A bullet has a large momentum
• Even though it has a small mass, it has a very
  large velocity

6
Comparing Momentum

• Which would have a larger momentum
• A 10 mph bowling ball or a 10 mph ping-pong ball?
  Which is harder to stop?
• Two cars of the same mass, one moving at 60 mph
  and the other moving at 30 mph?

7
Conservation of Momentum

• The total momentum of any given system will
  remain constant unless acted upon by an external
  force.
• or
• The momentum before a collision is equal to the
  momentum after a collision.

8
Example

• When a bullet is fired from a gun, what happens?

9
Example

• The bullet moves in the forward direction and the
  gun kicks backward. Before firing, the total
  momentum of the system was zero. When the bullet
  is fired it gains some momentum (due to velocity
  acquired by it). In response, the gun moves in
  the opposite direction such that its momentum is
  equal in magnitude but opposite in direction to
  the momentum of the bullet.

10
Momentum Transfer

• Remember Momentum is transferred not lost
• Conservation of Momentum Video