I would like help

Question

A ball is thrown from a height of
70
feet with an initial downward velocity of
4/fts
. The ball's height
h
(in feet) after
t
seconds is given by the following.
=h−70−4t16t2
How long after the ball is thrown does it hit the ground?
Round your answer(s) to the nearest hundredth.
(If there is more than one answer, use the "or" button.)

Answer 1

I think you have either copied or typed the problem incorrectly.

With that assumption that h = 70 - 4t - 16t², the ball will hit ground when h= 0

Use the quadratic formula to get one negative root (to be ignored) and one positive root approximately 1.97

Don't remember the quadratic formula?

For this problem it is (4±√(16 + 4*16*70))/-32