1. Impulse

2. Impulse is the change in momentum over time
Momentum changes due to a force, so you can also think of impulse as force x time

3. Impulse = change in momentum
Momentum = mass· velocity
P = m· v
Imp = mvf – mvi Units = Ns

4. Imp = mvf – mvi Imp = .5(40) - .5(0) = 20 Ns
In a penalty kick a soccer player increases the speed of the ball from 0 to 40 m/s. The mass of the soccer ball is .5 kg. What impulse does the soccer player give the ball?
Imp = mvf – mvi
Imp = .5(40) - .5(0) = 20 Ns

5. Impulse = Force x time
Imp = F x t
Units = Ns

6. If the soccer player is in contact with the ball for
If the soccer player is in contact with the ball for .1 second, what is the force exerted on the ball?
Imp = F x t
20 = F (.1)
200 N = F