A solid ball is released from rest and slides down a ramp that makes an angle of 50 degrees with respect to the horizontal. a) What is the minimum coefficient of static friction between the ramp and the ball for no slipping to occur? b) Would this coefficient of static friction be sufficient to stop a hollow ball (like a basketball or soccer ball) from slipping? Why or why not? c) Why does part a ask about the coefficient of static, not kinetic, friction?