Momentum Momentum is mass times velocity. Momentum is represented by p. p = mv Momentum is a vector quantity. The direction of momentum always matches the direction of velocity.

Momentum A small object traveling at a great speed has a high momentum. A large object traveling at a slow speed can have a small momentum.

Momentum If a bowling ball and a tennis ball are rolled on the floor with the same velocity, the bowling ball will have more momentum. The ball with the greater inertia will have the greater momentum. If the tennis ball is rolled with a much higher velocity, it may have more momentum than the bowling ball.

Momentum How can you increase momentum? A force must be applied to change the velocity of the object, which increases the momentum. Ex: A toy car is at rest. What is it’s momentum? Zero When you push on the car, what happens to the momentum of the car? It increases How was the car’s momentum changed? An external force was applied. If you stop the car, how has the car’s momentum changed?

Momentum FΔt = Δp = mvf – mvi The Impulse-momentum Theorem: F Δt = Δ p Force x time interval = change in momentum

Momentum A small force acting for a long time can produce the same change in momentum as a large force acting for a short time. Ex: Pushing a shopping cart – you can push for a short time with a great force and it will go some distance. If you push with a small force for a long time, it can go that same distance.

Momentum Momentum is the reason follow-through is important in sports. You can achieve a greater momentum with a smaller force. The longer a bat stays in contact with the ball, the greater the change in momentum. The longer a foot stays in contact with a soccer ball, the greater the change in momentum. The longer a hand stays in contact with a football, the greater the change in momentum.

Momentum According to FΔt = Δp = mvf – mvi Force is reduced when the time interval of an impact is increased. Throwing an egg into a bedsheet - YouTube

Momentum Ex: A 0.50 kg football is thrown with a velocity of 15 m/s to the right. A stationary receiver catches the ball and brings it to rest in 0.020 s. What is the force exerted on the ball by the receiver? G: m = 0.50 kg Vi = 15 m/s Vf = 0 m/s t = 0.020 s U: F E: FΔt = mvf – mvi S: F * 0.020 s = (0.50 kg)(0m/s) -(0.050 kg)(15 m/s) S: F = -380 N or 380 N to the left