mass spring system

lab04

I've a question.. and don't know what to do
An object of mas (m) is traveling on a horizontal surface. There is a coefficient of kinetic firction (mu) between the object and the surface. The object has speed (v) when it reaches (x=0) and encounters a spring. The object compress the spring, stop, and then recoils and travels in the opposite direction. When the object reaches (x=0) on its return trip, it stops.
Question: Find (k), the spring constant. Express (k) interms of (mu),(m), (g) and (v) Thanks

HallsofIvy

Alright what have you done? What formulas connect the various quantities?