A rock is thrown off of a 100 foot cliff with an upward velocity of 35 m/s. As a result its height after t seconds is given by the formula:
$h(t)=100+35 t- 5t^2$
What is its height after 5 seconds?
What is its velocity after 5 seconds?
(Positive velocity means it is on the way up, negative velocity means it is on the way down.)