will fan and medal!!!!!!!!!!!!!!!!!!!!!!!!!

A ball is rolled off the edge of a bridge, at which point it falls towards the ground 100 feet below. How long until the ball hits the ground, ignoring air resistance? Use the formula h=-16t^2+100 where h is the height of the ball in feet and t is the time in seconds since it starts falling.
A.
1.8 seconds
B.
2.5 seconds
C.
4.5 seconds
D.
6.3 seconds

Question

will fan and medal!!!!!!!!!!!!!!!!!!!!!!!!!

A ball is rolled off the edge of a bridge, at which point it falls towards the ground 100 feet below. How long until the ball hits the ground, ignoring air resistance? Use the formula h=-16t^2+100 where h is the height of the ball in feet and t is the time in seconds since it starts falling.
A.
1.8 seconds
B.
2.5 seconds
C.
4.5 seconds
D.
6.3 seconds

welshfella · Answer

when the ball hits the ground h = 0

anonymous · Answer

Set h = 0, then solve the quadratic using the quadratic formula.

mathmale · Answer

Question (serious question):  How high off the ground will the ball be when it hits the ground?

mathmale · Answer

You've got three great helpers here.  What next in your problem solution?

anonymous · Answer

is the answer t=-5/2 or 5/2?

anonymous · Answer

@mathmale