Warm up A 3.00 kg crate slides down a 7 m ramp. The height of the ramp is 5 m off the ground. The velocity of the crate at the bottom of the ramp is 5 m/s. Is there friction on the ramp and if what is that frictional force? 5 m 7 m Physics Honors AB Day 1/25/16-1/27/16 Impulse, Conservation of Momentum, & Collisions Agenda Momentum Def Example Impulse Impulse Momentum Theorem Conservation of Momentum Conservation of Energy Collisions Elastic and Inelastic Which person would be harder to stop if they were running the same velocity? Momentum Example An ostrich with a mass of 146 kg is running to the right with a velocity of 17 m/s. Find the momentum of the ostrich. Momentum is closely related to the Force Impulse Impulse Example A 0.4 kg soccer ball approaches a player horizontally with a velocity of 18 m/s to the left. The player strikes the ball and causes it to move in the opposite direction with a velocity of 22 m/s. What impulse was delivered to the ball by the player? Impulse Example A 2500 kg car traveling to the north is slowed down uniformly from an initial velocity of 20.0 m/s by a 6250 N braking force acting opposite the cars motion. Use the impulse-momentum theorem to answer the following questions What is cars velocity after 2.5 s? How long does it take the car to come to a complete stop? Impulse and Momentum Conservation of Momentum A 63 kg astronaut is in space and throws a 10 kg oxygen tank towards Earth with a speed of 12.0 m/s. Assuming the astronaut starts from rest, find the final velocity of the astronaut after the throw. Conservation of Momentum in Space Linear Momentum in Space Collisions Elastic Collision A 16 kg canoe moving to the left at 12 m/s makes an elastic head- on-collision with a 4.0 kg raft moving to the right at 6.0 m/s. After the collision, the raft moves to the left at 22.7 m/s. Disregard any water effects. Find the velocity of the canoe after the collision. Inelastic Collisions A 1500 kg car traveling at 15 m/s to the south collides with a 4500 kg truck that is initially at rest. The car and truck stick together and move together after the collisions. What is the final velocity of the two vehicle mass? Car Crash Video Physics of Car Crash