A 69.0-kg athlete leaps straight up into the air from a trampoline with an initial speed of 8.9 m/s. The goal of this problem is to find the maximum height she attains and her speed at half maximum height. What is the gravitational potential energy associated with the athlete?

A 230 g block is dropped onto a relaxed vertical spring that has a spring constant of k = 1.3 N/cm (see the figure). The block becomes attached to the spring and compresses the spring 14 cm before momentarily stopping. While the spring is being compressed, what work is done on the block by (a) the gravitational force on it and (b) the spring force? (c) What is the speed of the block just before it hits the spring? (Assume that friction is negligible.) (d) If the speed at impact is doubled, what is the maximum compression of the spring? (a) Number (b) Number (d) Number 3155 - 1.274 (c) Number 2.88 9 Units Units Units J J m/s Units m/s

A basketball player throws a basketball m = 1 kg straight up with an initial speed of v0 = 9.5 m/s. The ball leaves his hand at shoulder height h0 = 2.2 m. Let gravitational potential energy be zero at ground level. Give the total mechanical energy of the ball E in terms of maximum height hm it reaches, the mass m, and the gravitational acceleration g.

A 31 kg bear slides, from rest, 10 m down a lodgepole pine tree, moving with a speed of 3.0 m/s just before hitting the ground. (a) What change occurs in the gravitational potential energy of the bear-Earth system during the slide? (b) What is the kinetic energy of the bear just before hitting the ground? (c) What is the average frictional force that acts on the sliding bear?