Height and speed

Question

A toy rocket is shot vertically into the air from a launching pad 5 feet above the ground with an initial velocity of 112 feet 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)=-16t^2+112t+5. How long will it take the rocket to reach its maximum height? What is the maximum height?

Answer 1

Use the equation

 

t = -b / (2a)

 

where:

a = -16

b = 112

 

Plug in these values into the equation to solve for t to find the time of maximum height.

 

Then to find maximum height, evaluate h(t) at the time of maximum height.