A 58.0 kg person running at an initial speed of v, = 3.70 m/s jumps onto a m= 116 kg cart initially at rest (see figure below). The person slides on the cart's top surface and finally comes to rest relative to the cart. The coefficient of kinetic friction between the person and the cart is 0.470. Friction between the cart and ground can be neglected. (a) Find the final velocity of the person and cart relative to the ground. m/s (b) Find the frictional force acting on the person while he is sliding across the top surface of the cart. (c) How long does the frictional force act on the person? (d) Find the change in momentum of the person and the change in momentum of the cart. N-s (person) N-s (cart)

A 54.9-kg skater is standing at rest in front of a wall. By pushing against the wall she propels herself backward with a velocity of -1.93 m/s. Her hands are in contact with the wall for 1.09 s. Ignore friction and wind resistance. Find the average force she exerts on the wall (which has the same magnitude, but opposite direction, as the force that the wall applies to her). Note that this force has direction, which you should indicate with the sign of your answer. Number -9.72 Units

Kyle, a 95.0 kg football player, leaps straight up into the air (with no horizontal velocity) to catch a pass. He catches the 0.430 kg ball precisely at the peak of his jump, when he is 0.538 meters off the ground. He hits the ground 0.0333 metersaway from where he leapt. If the ball was moving horizontally when it was caught, how fast was the ball traveling?   ball's speed: ? m/s

A boy of mass m = 36 kg is standing initially at rest relative to the moving walkway, which has a constant horizontal speed u = 1.1 m/s. He decides to accelerate his progress and starts to walk from point A with a steadily increasing speed and reaches point B (a distance s = 29 m) with a speed dx/dt = v = 2.5 m/s relative to the walkway. During his acceleration he generates an average horizontal force F between his shoes and the walkway. Calculate the work done on the boy by the force F from an absolute viewpoint and then from a relative viewpoint. Explain the difference. Answers: Absolute viewpoint, Work = i Relative viewpoint, Work = i J