If a stone is dropped from a height of 650 feet, its height after t seconds is given by s = 650 − 16t2. Find its instantaneous velocity function.

Question

v(t) = __

Find its velocity at time t = 2.

v(2)= __ ft/sec

Answer 1

v(t) = s'(t) = derivative of -16t^2 + 650

v(t) = -32t

v(2) = -64

Answer 2

v(t) = s'(t) = -32t;

V(2) = -32·2 = - 64 feet/s