The height of a golf ball in the air can be modeled by the equation, where h is the height in the feet of the ball after t seconds.

a. how long is the ball in the air?

For this case we have the following equation:

h (t) = - 16t ^ 2 + 76t

We must find the time that was in the air.

For this we equate the equation to zero.

-16t ^ 2 + 76t = 0

We look for the roots of the polynomial.

For this, we rewrite:

-4t * (4t-19) = 0

Which roots are:

t = 0

t = 19/4

Therefore, the time it was in the air was:

t = 19/4

Answer:

t = 19/4 seconds