During a perfectly elastic collision between two bodies, which of the following statements is always true?       a. Kinetic energy is not conserved.     b. Kinetic energy is conserved and momentum is conserved.     c. Kinetic energy is conserved and momentum is not conserved.     d. Kinetic energy is not conserved and momentum is not conerved.   e. Kinetic energy is conserved.

A tennis player receives a shot with the ball (0.060 0 kg) traveling horizontally at 20.0 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 tennis racket? (b) Some work is done on the system of the ball and some energy appears in the ball as an increase in internal energy during the collision between the ball and the racket. What is the sum W Eint for the ball?

An object that has a small mass and an object that has a large mass have the same momentum. Which object has the largest kinetic energy?

(a) Calculate the momentum of a 2000-kg elephant charging a hunter at a speed of 7.50 m/s. (b) Compare the elephant's momentum with the momentum of a 0.0400-kg tranquilizer dart fired at a speed of 600 m/s. (c) What is the momentum of the 90.0-kg hunter running at 7.40 m/s after missing the elephant?

(a) What is the mass of a large ship that has a momentum of 1.60109kgm/s, when the ship is moving at a speed of 48.0 km/h? (b) Compare the ship's momentum to the momentum of a 1100-kg artillery shell fired at a speed of 1200 m/s.

In a laboratory, a cart collides with a wall and bounces back. Figure P11.10 shows a graph of the force exerted by the wall versus time. a. Find the impulse exerted by the wall on the cart. b. What is the average force exerted by the wall on the cart? c. If the cart has a mass of 0.448 kg, what is its change in velocity? d. Make a sketch of the situation. Include a coordinate system and explain the significance of the signs in parts (a) through (c). FIGURE P11.10

A massive tractor is rolling down a country road. In a perfectly inelastic collision, a small sports car runs into the machine from behind. (i) Which vehicle experiences a change in momentum of larger magnitude? (a) The car does. (b) The tractor does. (c) Their momentum changes are the same size. (d) It could be either vehicle. (ii) Which vehicle experiences a larger change in kinetic energy? (a) The car does. (b) The tractor does. (c) Their kinetic energy changes are the same size. (d) It could be either vehicle.

A 65.0-kg boy and his 40.0-kg sister, both wearing roller blades, face each other at rest. The girl pushes the boy hard, sending him backward with velocity 2.90 m/s toward the west. Ignore friction. (a) Describe the subsequent motion of the girl. (b) How much potential energy in the girls body is converted into mechanical energy of the boygirl system? (c) Is the momentum of the boygirl system conserved in the pushing-apart process? If so, explain how that is possible considering (d) there are large forces acting and (e) there is no motion beforehand and plenty of motion afterward.

A 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 tennis racquet? (b) What work does the racquet do on the ball?

Two gliders are set in motion on a horizontal air track. A light spring of force constant k is attached to the back end of the second glider. As shown in Figure P9.41, 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 v at maximum compression, (b) the maximum compression xmax, and (c) the velocity of each glider after m1 has lost contact with the spring. Figure P9.41