Physics – Momentum – Unit Review Kowinsky NAME: ___________________ Pd: _____ Concepts: 1) Define impulse 2) During what type of collision is Energy not conserved? 3) What type of collision applies more force, an inelastic or an elastic (bouncing)? Why? 4) Give 2 examples of a Perfectly elastic collision, and two examples of inelastic collisions. 5) If the time of impact during a collision increases, what happens to the force? 6) What is the momentum of a stationary object? 7) A truck loaded with sand is on a straight path. A) What happens to the momentum of the truck if the truck’s velocity is increasing? B) What happens to the momentum of the truck if sand leaks at a constant rate through a hole in the truck bed while the truck maintains a constant velocity? 8) For safety reasons, it is recommended that a heavy load is not regularly carried in the back of a pickup truck. Explain why in terms of momentum. 9) How do car bumpers that collapse on impact help protect the driver? 10) Who is Pelton, what did he do? Impulse: 11) A football punter accelerates a .55 kg football from rest to a speed of 8 m/s in .25 s. What force does the punter exert on the ball? (18 N) 12)What is the momentum of a proton with mass 1.67 x10-27 kg moving with a velocity of 5x106 m/s upward? (8.35x10-21 kg m/s). Physics – Momentum – Unit Review NAME: ___________________ Kowinsky Pd: _____ 13) If a .147 kg baseball has a momentum of 6.17 kg m/s as it is thrown from home to second base, what is its velocity? (42 m/s toward second base) 14) A .025 kg golf ball moving at 18 m/s crashes through a windows of a house in 5x1—4 s. After the crash, the ball continues the same directions with a speed of 10 m/s. What is the force exerted on the ball by the window? (400 N). Collisions: 15) An ice skater (ignore friction) is moving to the right with a velocity of 2.5 m/s. the ice skater throws a .15 kg snowball to the right with a velocity of 32 m/s. What is the velocity of the ice skater after throwing the snowball? (2.43 m/s to the right). 16) A 95 kg fullback moving south with a speed of 5 m/s has a perfectly inelastic collision with a 90 kg opponent running north a 3 m/s. How much KE was lost during the collision? (1400 J) 17) A .015 kg marble moving to the right at .225 m/s makes an elastic head on collision with a .03 kg shooter marble moving to the left at .18 m/s. After the collision, the smaller marble moves to the left at .315 m/s. What is the velocity of the .03 kg marble after the collision. Since this is an elastic collision verify that KE is conserved. (.09 m/s to the right, KEi = .00087 J = KEf) 18.) Object A has a mass of 5 kg, and is moving at a velocity of 3 m/s at 30o to the horizontal. Object B has a mass of 3 kg, and is moving at a velocity of 5 m/s at 200o to the horizontal. The two objects collide. Object B bounces at a velocity of 2 m/s at 70o to the horizontal. Determine the velocity of object A after the collision.