Question

If a baseball is dropped from a helicopter 625 feet above ground, then its distance in feet form the ground t seconds later is modeled by -16t^2+625. How long after the ball is dropped will it hit the ground?

A. 1.56 seconds

B. 6.25 seconds

C. 9 seconds

D. 39.06 seconds

Answer 1

They are really asking \[-16t^{2}+625=0\].

Answer 2

So how do you solve it then?

Answer 3

As you would any other quadratic equation.
You'll get two solutions. A negative and a positive. You'll take the positive solution because time is positive.

Answer 4

SO is the answer D

Answer 5

No, B