In a stunt, three people jump off a platform and fall 9.9 m onto a large air bag A fourth person at the other end of the air bag, the “flier,” is launched 17 m vertically into the air Assume all four people have a mass of 75 kg (a) What fraction of the mechanical energy of the three jumpers is transferred to the mechanical energy of the flier? (b) What is the total momentum of the three jumpers just before they land on the air bag? Let upward be the positive direction (c) What is the momentum of the flier just after launch? (d) Notice that momentum is not conserved during this stunt, unless you include the Earth What impulse is delivered to the jumpers-flier system by the Earth at the instant of the launch?
Want to see the full answer?
Check out a sample textbook solutionChapter 9 Solutions
Physics (5th Edition)
Additional Science Textbook Solutions
Essential University Physics: Volume 2 (3rd Edition)
University Physics (14th Edition)
College Physics
An Introduction to Thermal Physics
Essential University Physics: Volume 1 (3rd Edition)
- Describe a system for which momentum is conserved but mechanical energy is not. Now the reverse: Describe a system for which kinetic energy is conserved but momentum is not.arrow_forwardTwo gliders are set in motion on a horizontal air track. A spring of force constant k is attached to the back end of the second glider. As shown in Figure P8.48, the first glider, of mass m1, moves to the right with speed v1, and the second glider, of mass m2, moves more slowly to the right with speed v2. When m1 collides with the spring attached to m2, the spring compresses by a distance xmax, and the gliders then move apart again. In terms of v1, v2, m1, m2, and k, find (a) the speed rat maximum compression, (b) the maximum compression xmax, and (c) the velocity of each glider after m1 has lost contact with the spring.arrow_forwardA boy standing at one end of a floating raft that is stationary relative to the shore walks to the opposite end of the raft, away from the shore. As a consequence, the raft (a) remains stationary, (b) moves away from the shore, or (c) moves toward the shore. (Hint: Use conservation of momentum.)arrow_forward
- Two objects are connected by a light string passing over a light, frictionless pulley as shown in Figure P8.7. The object of mass m1 = 5.00 kg is released from rest at a height h = 9.00 m above the table. Using the isolated sys-tem model, (a) determine the speed of the object of mass m2 = 3.00 kg just as the 5.00-kg object hits the table and (b) find the maxi-mum height above the table to which the 3.00-kg object rises.arrow_forwardA glider of mass m is free to slide along a horizontal air track. It is pushed against a launcher at one end of the track. Model the launcher as a light spring of force constant k compressed by a distance x. The glider is released from rest. (a) Show that the glider attains a speed of v = x(k/m)1/2. (b) Show that the magnitude of the impulse imparted to the glider is given by the expression I = x(km)1/2. (c) Is more work done on a cart with a large or a small mass?arrow_forwardA tennis ball of mass mt is held just above a basketball of mass mb, as shown in Figure P8.22. With their centers vertically aligned, both are released from rest at the same moment so that the bottom of the basketball falls freely through a height h and strikes the floor. Assume an elastic collision with the ground instantaneously reverses the velocity of the basketball while the tennis ball is still moving down because the balls have separated a bit while falling. Next, the two balls meet in an elastic collision. (a) To what height does the tennis ball rebound? (b) How do you account for the height in (a) being larger than h? Does that seem like a violation of conservation of energy? Figure P8.22arrow_forward
- A boy of mass mb and his girlfriend of mass mg, both wearing ice skates, face each other at rest while standing on a frictionless ice rink. The boy pushes the girl, giving her a velocity vg toward the east. Assume that mb mg. (a) Describe the subsequent motion of the boy. (b) Find expressions for the final kinetic energy of the girl and the final kinetic energy of the boy, and show that the girl has greater kinetic energy than the boy. (c) The boy and girl had zero kinetic energy before the boy pushed the girl, but ended up with kinetic energy after the event. How do you account for the appearance of mechanical energy?arrow_forwardA table-tennis ball is thrown at a stationary bowling ball. The table-tennis ball makes a one-dimensional elastic collision and bounces back along the same line. Compared with the bowling ball after the collision, does the table-tennis ball have (a) a larger magnitude of momentum and more kinetic energy, (b) a smaller magnitude of momentum and more kinetic energy, (c) a larger magnitude of momentum and less kinetic energy, (d) a smaller magnitude of momentum and less kinetic energy, or (e) the same magnitude of momentum and the same kinetic energyarrow_forwardA ball of mass m is thrown straight up into the air with an initial speed v0. (a) Find an expression for the maximum height reached by the ball in terms of v0 and g. (b) Using conservation of energy and the result of part (a), find the magnitude of the momentum of the ball at one-half its maximum height in terms of m and 0.arrow_forward
- A car and a large truck traveling at the same speed collide head-on and stick together. Which vehicle undergoes the larger change in the magnitude of its momentum? (a) the car (b) the truck (c) the change in the magnitude of momentum is the same for both (d) impossible to determine without more information.arrow_forwardTwo blocks of masses m and 3m are placed on a frictionless, horizontal surface. A light spring is attached to the more massive block, and the blocks are pushed together with the spring between them (Fig. P8.7). A cord initially holding the blocks together is burned; after that happens, the block of mass 3m moves to the right with a speed of 2.00 m/s. (a) What is the velocity of the block of mass m? (b) Find the systems original elastic potential energy, taking m = 0.350 kg. (c) Is the original energy in the spring or in the cord? (d) Explain your answer to part (c). (e) Is the momentum of the system conserved in the bursting-apart process? Explain how that is possible considering (f) there are large forces acting and (g) there is no motion beforehand and plenty of motion afterward? Figure P8.7arrow_forwardA tennis player receives a shot with the ball (0.060 0 kg) traveling horizontally at 50.0 m/s and returns the shot with the ball traveling horizontally at 40.0 m/s in the opposite direction. (a) What is the impulse delivered to the ball by the racket? (b) What work does the racket do on the hall?arrow_forward
- Principles of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and Engineers with Modern ...PhysicsISBN:9781337553292Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningPhysics for Scientists and EngineersPhysicsISBN:9781337553278Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Physics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage LearningCollege PhysicsPhysicsISBN:9781305952300Author:Raymond A. Serway, Chris VuillePublisher:Cengage LearningPhysics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage Learning