[问答题]
A ball is attached to aes *ft32t2ysg horizontal cord of length L whhzh jdq /-/8ybose other end is fixed (Fig. 6–43).
/h /bj- zhqyd8 (a) If the ball is released, what will be its speed at the lowest point of its path?
(b) A peg is located a distance h directly below the point of attachment of the cord. If h=0.8L what will be the speed of the ball when it reaches the top of its circular path about the peg?
