1. Momentum and Impulse

2. Answer Me!!! Forces cause objects to start moving. What keeps an object moving after the force is no longer applied?

3. Momentum Momentum is the product of an object’s mass and velocity p = mv  p is momentum  m is mass  v is velocity Momentum is a vector quantity measured in kg. m/s

4. Impulse Impulse (J) is the change in an object’s momentum: J =  p J = m  v Also, Impulse can be calculated using: J = Ft  J is impulse  F is Force  t is time

5. Conservation of Momentum In a closed system, the total change in momentum of the system is zero. In other words, the total momentum before an event is equal the total momentum after an event if no “outside forces” are exerted. p before = p after

6. Practice Problem 1 A rocket with a mass of 1,000 kilograms is moving at a speed of 20 meters per second. Calculate the momentum of the rocket.

7. Practice Problem 2 An unbalanced 6.0 newton force acts eastward on an object for 3.0 seconds. Calculate the impulse produced by the force.

8. Final Thought… A 100 kg clown is fired from a 500 kg cannon. If the clown’s speed after firing is 15 m/s, what is the recoil speed of the cannon?

9. Answer Me!!! A 4.0-kilogram cart moving to the right at 3.0 m/s and a 6.0-kilogram cart moving to the left at 3.0 m/s. When the two carts collide they lock together. What is the total momentum of the system after the collision?