1. Ch. 6 Momentum and Impulse

2. Momentum

3. Momentum – the product of an object’s mass and velocity
it is a vector quantity
The direction is the same as the velocity
The symbol is “p”

4. Formula
momentum = mass x velocity
p = m x v
(kg•m/s) kg m/s

5. Impulse – the product of the force and
the time over which it acts on
an object Δp F= Δt

6. Impulse

7. The larger the mass, the greater the momentum compared to a less massive object with the same velocity.
If mass is constant, the larger the velocity the greater the momentum.
A change in momentum over a longer time requires less force

8. A change in momentum takes force and time.
The larger the momentum, the more force and/or time it will take to change the momentum

9. Force and time act together to change momentum.

10. FΔt = Δp FΔt = pf - pi FΔt = mvf - mvi
Stopping times and distance depend on the impulse-momentum theorem
Impulse = change in momentum
FΔt = Δp
FΔt = pf - pi
FΔt = mvf - mvi

11. A large force over a short time will have the same effect as a small force over a long time.

12. A 2250 kg pickup truck has a velocity of 25 m/s to the east
A 2250 kg pickup truck has a velocity of 25 m/s to the east. What is the momentum of the truck?

13. A 1400 kg car moving westward with a velocity of 15 m/s collides with a utility pole and is brought to rest in 0.30 s. What is the force exerted on the car during the collision?

14. A 2250 kg car traveling west slows down uniformly from 20. 0 m/s to 5
A 2250 kg car traveling west slows down uniformly from 20.0 m/s to 5.00 m/s. How long does it take the car to slow down if the force on the car is N to the east?