A box of mass m = 38 kg which is sliding on a horizontal rough surface and momentarily comes to a stop after compressing the spring by a distance of 120 mm. The spring has a spring constant k = 25 kN/m and is initially in its equilibrium state. The initial speed of the box is 3.0 m/s.
a) What is the work done by the spring as the box is brought to a stop?
b) Write an expression for the work done by friction during the stopping of the box (in terms of the coefficient of kinetic friction).
c) Determine the coefficient of friction between the box and the surface.