Harmonic motion. Consider a person standing at rest on the frame of a trampoline with bent knees. When cued, she jumps into the air, landing in the center of the trampoline, which bends under her weight and launches her (vertically) into the air. She relaxes, not making any effort to jump, and passively bounces up and down on the center of the trampoline several times, eventually coming to a standstill.

Describe the trajectory of the jumper over the first three up / down cycles, explaining which of Newton’s laws apply at any given time, and where the forces involved in the applications of those laws come from.

I figure out that the laws were Newton's 2 and 3 laws. Please Help me?

We do not complete homework for students, however, we do point them in the right direction. I found a great primer on the Physics of Trampolines (http://www.trampolinesafety.com/the-physics-a-trampoline).