A 150-g block is projected up a ramp with an initial speed of 6.2 m/s. The coefficient of kinetic friction between the ramp and the block is 0.23.
(a) If the ramp is inclined 21° with the horizontal, how far along the surface of the ramp does the block slide before coming to a stop?
(b) What is the minimum coefficient of static friction between the block and the ramp if the block is not to slide back down the ramp?