A box of mass 10kg starts from rest and slide down a plane angled at 45 degrees to the horizontal. the box slides 2m down the plane before it encounters a spring with constant k=500 N/m which causes it to come to rest. What will the maximum compression of the spring be:

Question

A box of mass 10kg starts from rest and slide down a plane angled at 45 degrees to the horizontal. the box slides 2m down the plane before it encounters a spring with constant k=500 N/m which causes it to come to rest. What will the maximum compression of the spring be:
a) assuming the co-efficient of kinetic friction between the plane and the box is zero (ie: frictionless)
b) assuming the co-efficient of kinetic friction between the plane and box is 0.5