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

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