1985M2. An apparatus to determine coefficients of friction is shown above. The box is slowly rotated counterclockwise. When the box makes an angle θ with the horizontal, the block of mass m just starts to slide, and at this instant the box is stopped from rotating. Thus at angle θ, the block slides a distance d , hits the spring of force constant k , and compresses the spring a distance x before coming to rest. In terms of the given quantities, derive an expression for each of the following.
a. μs the coefficient of static friction.
b. ΔE, the loss in total mechanical energy of the block-spring system from the start of the block down the incline to the moment at which it comes to rest on the compressed spring.
c. μk, the coefficient of kinetic friction.