Question

Hitting the baseball over the lights

Meanwhile, at the ballpark, Juan was practicing his hitting while talking to the girls
standing around watching. He started telling them how he hit the ball over the 50 foot
light tower yesterday. The girls were unsure that he really did that.
The formula for this hit is: H(x)=-16x^2+60x+4 where h is the height of the ball and x is the number of seconds the ball is in the air.
How long did the ball actually hang in the air?

Answer 1

Approximately 3.8 seconds

Explanation:

H(x)=-16x^2+60x+4

We want to find when the ball hits the ground, or where the zeros are

0 =-16x^2+60x+4

Using the quadratic formula

-b ±sqrt(b^2 -4ac)

---------------------------

2a

-60 ±sqrt(60^2 -4*-16*4)

---------------------------

2(-16)

-60 ±sqrt(3600+256)

---------------------------

-32

-60 ±sqrt(3856)

---------------------------

-32

We want the positive value for time

-60-62.09669879

---------------------------

-32

3.815521837

Approximately 3.8 seconds