GENERAL PHYSICS 1 F23 Chapter 8 HW 1,2,3,4 1. Two objects have the same kinetic energy, but different linear momenta. Which of the objects has the larger mass, the one with the larger linear momentum or the one with the smaller linear momentum? Explain. 2. Two objects have the same linear momentum, but kinetic energies. Which of the objects has the larger mass, the one with the larger kinetic energy or the one with the smaller kinetic energy? Explain.3. An object having a mass of 8.00 [kg ] is moving in the negative x direction at a 5. Suppose, now, that after exiting the plane the parachute of the jumper in Question speed of 40.0 [m/s] when it undergoes a collision that lasts 0.250 [s]. After the #4 fails to open and, as he falls, he achieves a downward terminal velocity of 70.0 collision the object is moving in the negative x direction at 50.0 [m/s]. (a) What is [m/s] before hitting the ground. Once again assume that the time to come to a the impulse (magnitude and direction), and (b) what is the average force complete stop is 150. x 10-3 [s]. (a) What is his impulse on landing this time? (b) (magnitude and direction) acting on the object during the collision. To achieve this impulse, what is the average impulsive force acting on him as he comes to a stop? (c) What is the ratio of the impulsive force he experiences without the parachute to that experienced with the parachute? 5. A 500. [kg] surveillance satellite is separated from its 1000. [kg] booster rocket by explosive bolts. If the relative speed at which the satellite and booster rocket separate is 1.50 [m/s], what is the impulse provided by the explosive volts? 4. A 65.0 [kg] parachutist lands with a downward vertical velocity of 10.0 [m/s] and comes to a complete stop in 150. x 10-3 [s]. (a) What is his impulse on landing? (b) To achieve this impulse, what is the average impulsive force acting on the parachutist as he comes to a stop? (c) What is the ratio of the impulsive force to his weight?Page 4 of 7 6. The coefficient of restitution of a ball is defined as the ratio of the rebound speed 8. A head-on elastic collision occurs between two objects. Before the collision object to the incident speed when the ball collides with a rigid surface. If a handball has #1 has a mass of 0.250 [kg] and is moving to the right with a speed of 1.00 [m/s], a coefficient of restitution of 0.50, what fraction of the ball's kinetic energy is lost while object #2 has a mass of 0.750 [kg] and is moving to the left with a speed of when it rebounds straight back off the wall of a handball court? 1.00 [m/s]. What are the velocities of the two objects after the collision? 7. Two equal masses collide in an inelastic collision. The initial velocity of object #1 is v while object #2 is initially stationary. (a) What is the final velocity of the two 9. Car #1 with a mass of 1.50 x 103 [kg] is travelling east at a speed of 25.0 [m/s]. It objects after the inelastic collision? (b) What fraction of the initial linear collides in the middle of an intersection with Car #2 which has a mass of 2.50 x momentum of the system is lost during the collision? (c) What fraction of the 103 [kg] and which enters the intersection travelling north at a speed of 20.0 initial kinetic energy of the system is lost during the collision? [m/s]. (a) Find the magnitude and direction of the velocity of the wreckage, assuming that after the collision the two cars stick together and that frictional forces can be neglected. (b) How much kinetic energy is lost in the collision? (c) How much linear momentum is lost in the collision?Page 6 of 7 (d) Sketch a velocity vs time graph of the puck's y-velocity. 10. A hockey puck of mass 0.160 [kg] is travelling to the east with speed 2.50 [m/s] on the surface of a frictionless frozen pond when it receives a sharp 2.00 [N] force to the north that lasts 0.100 [s]. (a) What is the magnitude of the puck's y-velocity 1.00 [s] after the impulse occurs? (e) At what angle from east is the puck travelling after the impulse occurs? (b) What is the magnitude of the puck's x-velocity 1.00 [s] after the impulse occurs? (c) Sketch a velocity vs time graph of the puck's x-velocity