42. A5.0 kgblock of steel slides down a ramp with acceleration 0.40 m / s2directed down the ramp. The ramp makes an angle ofo37with the horizontal. What is the coefficient of kinetic friction between the block and the ramp?
(A) 0.50
(B) 0.70
(C) 0.25
(D) 0.75
(E) 5.0