Question

Vanessa throws a tennis ball in the air. the function h(t) = -16t2 + 45t + 7 represents the distance, in feet, that the ball is from the ground at any time t. at what time, to the nearest tenth of a second, is the ball at its maximum height? t = seconds listen submit answer previous next

Answer 1

Given that height, h(t) of a tennis ball is modeled by the equation h(t)=-16t^2 + 45t + 7, the time taken for the ball to reach maximum height will found as follows:
at maximum height:
h'(t)=0
but from the equation:
h'(t)=-32t+45=0
solving for t we get
t=45/32
t=1.40625~1.4 seconds
Thus the time taken to reach maximum height is 1.4 seconds