bellringer 9/30
DESCRIPTION
Bellringer 9/30. A skier leaves the horizontal end of a ramp with a velocity of 25.0m/s East and lands 70.0 m from the base of the ramp. How high is the end of the ramp from the ground?. Chapter 6: Momentum and Collisions. Linear Momentum (p): p= mv Momentum = mass x velocity - PowerPoint PPT PresentationTRANSCRIPT
Bellringer 9/30
• A skier leaves the horizontal end of a ramp with a velocity of 25.0m/s East and lands 70.0 m from the base of the ramp. How high is the end of the ramp from the ground?
Chapter 6: Momentum and Collisions
• Momentum – the product of the mass and velocity of an object
• Vector quantity – direction matches the velocity
Linear Momentum (p):p=mv
Momentum = mass x velocitySI units: kg●m/s
Momentum
• If both of these objects are moving down the street at the same speed… which has the greater momentum?
• What about if the Mack truck is at rest… what object has the greatest momentum?
Roll Tide!!
Practice Problems
• A 2250 kg pick up truck has a velocity of 25 m/s to the east. What is the momentum of the truck?
p = 5.6x104 kg●m/s to the east
Practice
• A 21 kg child on a 5.9 kg bike is riding with a velocity of 4.5 m/s to the northwest. What is the total momentum of the child and
the bike together? What is the momentum of the child? What is the momentum of the bike?
Impulse-Momentum Theorem
• Impulse = product of the force and the time over which the force acts on an object
Impulse-Momentum TheorenFΔt= Δp or F Δt= Δp=mvf -mvi
Force x time interval = change in momentum
Practice
• A 1400 kg car moving westward with a velocity of 15m/s collides with a utility pole and is brought to rest in 0.30s. Find the force exerted on the car during the collision.
F = 7.0 x 104 N to the east
Stopping Distance
• Stopping times and distance depend on impulse momentum theorem
• Force is reduced when the time interval of impact is increased
Practice
• A 2240 kg car traveling west slows down uniformly from 20.0m/s to 5.00m/s. How long does it take the car to decelerate if the force on the car is 8410 N to the east? How far does the car travel during the deceleration?
Impulse-Momentum Theorem