A 32-kg girl stands on a 7-kg wagon holding two 13.5-kg weights. She throws the weights horizontally off the back of the wagon at a speed of 9.0 m/s relative to herself. A) Assuming that the wagon was at rest initially, what is the speed of the girl after she throws both weights at the same time?                             B) Assuming that the wagon was at rest initially, what is the speed with which the girl will move after she throws the weights one at a time, each with a speed of 9.0 m/s relative to herself?

Particle A and particle B are held together with a compressed spring between them. When they are released, the spring pushes them apart, and they then fly off in opposite directions, free of the spring. The mass of A is 4.00 times the mass of B, and the energy stored in the spring was 46 J. Assume that the spring has negligible mass and that all its stored energy is transferred to the particles. Once that transfer is complete, what are the kinetic energies of each particle? (a) particle A --------- J(b) particle B --------- J

A 2.76-kg steel ball strikes a massive wall at 10.0 m/s at an angle of θ = 60.0° with the plane of the wall. It bounces off the wall with the same speed and angle (see the figure below). If the ball is in contact with the wall for 0.176 s, what is the average force exerted by the wall on the ball?

Particle A has mass m and moves directly to the right with speed v > 0. Particle B has one fourth the mass of Particle A and moves directly to the right with twice the speed of Particle A. Which of the following statements are true? (Pick two.) Particle A has greater momentum than Particle B. Particle B has greater momentum than Particle A. Both particles have the same momentum. Particle A has greater kinetic energy than Particle B. Particle B has greater kinetic energy than Particle A. Both particles have the same kinetic energy.

A bullet of mass mb is fired horizontally with speed vi at a wooden block of mass mw resting on a frictionless table. The bullet hits the block and becomes completely embedded within it. After the bullet has come to rest relative to the block, the block, with the bullet in it, is traveling at speed uf. (Figure 1) Figure Before collision mb mw 1 of 1 After collision ▼ Part A Which of the following best describes this collision? View Available Hint(s) Operfectly elastic O partially inelastic Operfectly inelastic Submit Part B Which of the following quantities, if any, are conserved during this collision? ►View Available Hint(s) Okinetic energy only O momentum only Okinetic energy and momentum Oneither momentum nor kinetic energy Submit P Pearson

After a 70-kg person steps from a boat onto the shore, the boat moves away with a speed of 0.70 m/sm/s with respect to the shore. If the same person steps from the shore onto the boat, the person and the boat move away from the shore at a speed of 0.50 m/sm/s. Assume that the initial speed of the person with respect to the shore is the same in both cases and that the person is moving in a horizontal direction. A. Determine the mass of the boat. B. Determine the speed of the person.

Two blocks of masses M and 3M are placed on a horizontal, frictionless surface. A light spring is attached to one of them, and the blocks are pushed together with the spring between them. A cord holding them together is burned, after which the block of mass 3M moves to the right with a speed of 55.1 m/s. What is the speed of the block of mass M?