A small block with mass 0.4 kilogram is located against a compressed spring at the bottom of a 37o incline. The compressed spring has 50 Joule of elastic potential energy stored in it. The spring is released and the block moves a distance of 12 meter along the incline before momentarily coming to rest.
a) Determine how much work does the friction force do on the block during the motion?
b) Determine what is the coefficient of kinetic friction between the block and the incline?