Kwok is standing on top of a $160$-foot building and throws a tennis ball straight up with an initial velocity of $24$ ft/sec.

1. How far up does the tennis ball go before it turns around and starts to come down?

   Hint (a):

   The tennis ball turns around when $v(t) = 0$.

2. How fast is it going when it hits the ground below?

   Hint (b):

   Evaluate $v$(time of impact). Let $h(t) = 0$ to find the time of impact.