During terrible weather at a ski-flying world championship, a ski jumper tried to adjust for bad conditions midway down the ramp but completely lost control and tumbled wildly off the side at its bottom into a scattering crowd. The 73-kg jumper left the ramp about 45 m lower than his starting position. If the ski jumper had simply fallen straight down 45-m rather than skiing down a ramp, would his kinetic energy increase?

Firecracker a. A firecracker is at rest on a frictionless horizontal table. The firecracker explodes into two pieces of unequal mass that move in opposite directions on the table. Before i. Is the net force on the left piece always zero? Explain. After I1. Is the net force on the system consisting of both pieces always zero? Explain. iii. Is the momentum of the left piece conserved? Explain. 1V. Is the momentum of the system consisting of both pieces conserved? Explain.

During an Olympic 100-m sprint race, Usain Bolt, the world record holder in that race, quickly accelerates to his top speed of 12.4 m/s. Analysis of his technique has shown that each of his feet make contact with the ground for 0.0800 s, exerting a force of magnitude 2.80 x 10° N during this contact. This allows the 94.0 kg Bolt to leap forward and remain airborne for 0.120 s until the next foot touches the ground. (Ignore air resistance.) (a) What are the magnitudes of the horizontal and vertical components of the force (in N) Bolt's feet exert on the ground? (Round your answers to at least three significant figures.) horizontal N vertical (b) Assuming that the sprinter accelerates at a constant rate while his feet are in contact with the ground and does not slow down when he is airborne, by what amount does Bolt's horizontal speed (in m/s) increase with each step? (Round your answer to at least three significant figures.) m/s (c) Assuming that the sprinter's speed increases at a…

A 0.430-kg soccer ball is kicked at an initial speed of 34.0 m/s at an angle of 35 degrees to the horizontal. What is the kinetic energy at the apex of its trajectory?