Question

A ball is thrown in the air from the top of a building. Its height, in meters above ground, as a function of time, in seconds, is given by

h(t) = −4.9t2 + 12t + 10.

How long does it take to reach maximum height? (Round your answer to three decimal places.)

Answer 1

1.225m

Explanation:

Maximum height is reached at time t when the derivative of equation is 0

`(dh)/(dt)  = - 9.8t + 12\\`

- 9.8t + 12 = 0

-9.8t = -12

Divide through by - 9.8

`(-9.8t)/(- 9.8)  = (-12)/(-9.8)`

t = 1.225m to 3 decimal places