Question

THe function h(t)=-16t^2+v0t+h0 describes the height in feet above the ground h(t) of an object thrown vertically from a height of h0 feet, with an initial velocity of v0 feet per second, if there is no air friction and t is the time in seconds sine the object was thrown. A ball is thrown upward from a 100-foot tower at a velocity of 60 feet per second. How many seconds will it take for the ball to reach the ground?

Answer 1

0 = 100 + 60 t - 16 t^2

16 t^2 - 60 t - 100 = 0

4 t^2 - 15 t -25 = 0

(4 t + 5)(t - 5) = 0

t = 5

Answer 2

t=5