Question

A golf ball is hit with an initial velocity of 80 ft/sec.Use the equation h(t)=80t-16t^2 where h(t) is the height of the object in feet and t is the time in seconds. How long will it take for the ball to hit the ground?

Answer 1

The ball takes 5 seconds to hit the ground

Explanation:

The equation to model the height of a golf ball in time t is:

`h(t)=80t-16t^2`

There are two moments when the height is zero: At launch time and when it hits the ground. To find the last time, we equate:

`80t-16t^2=0`

Factoring out t:

`t(80-16t)=0`

It gives us two solutions:

t=0

`80-16t=0`

Solving:

`-16t=-80`

`t=-80/(-16)=5`

t = 5 sec

Thus, the ball takes 5 seconds to hit the ground