Mechanical Energy: Trampoline Artist Jumps and Depresses Spring

[rphmy]

A 75-kg trampoline artist jumps vertically upward from the top of a platform with a speed of 5.0 m/s. (a) how fast is he going as he lands on the trampoline 3.0 m below (Fig. 6-23)? (b) If the trampoline behaves like a spring of spring constant 5.2x10^4 N/m, how far does he depress it?

 

[pixel01]

I think this is a kind of homework