Applications of quadratics another toy rocket

Question

 A toy rocket is shot vertically into the air from a launching pad 5 feet above the ground with an initial velocity of 136 per second. The height h in feet of the rocket above the ground at t seconds after launch is given by the function h(t) = -16t² + 136t +5  How long will it take the rocket to reach its maximum height? What is the maximum height? 

The rocket reaches its maximum height at ___ seconds after launch. 

Answer 1

The maximum height is reached at the vertex of the h-t parabola, which is at

 

t = -136/[2(-16)] s = ? s

 

Evaluate t, and plug it into the h(t) expression.  The value of h(t) at this t is h_max.