A slippery plastic block is resting on a ramp that makes an angle of 20° with the horizontal. The coefficient of static friction between the block and the ramp is 0.2. The coefficient of kinetic friction is 0.15. Will the block start sliding on its own?
If you found that the block slid in part a, calculate its acceleration. If not, then calculate the minimum angle the ramp must have to start the block sliding.

If you answer with something else that isn't the answer, I'll report your answer.