A spring with negligible mass has a constant of 105 N/m. It has been compressed horizantally with a 2 kg mass for a distance of 0.1m. If the mass has moved after release for a distance of 0.25m, what is the coefficient of kinetic friction between mass and horizontal surface.
F=-kx (spring force)
f= C N, f is friction, C is the kinetic friction coefficient, and N is the force exerted on the mass by the horizontal surface