Question

A girl throws a ball vertically at 10 m/s from a roof of a building 20 m high.
(a.) How long will it take the ball to reach the ground?
(b.) What will its velocity be when it strikes the ground?

Answer 1

So the ball goes up from the roof and then falls down?

Answer 2

yes

Answer 3

How do I solve this?

Answer 4

h(t) = -4.9t^2 + 10t + 20

Factor this one...

Answer 5

where did you get -4.9?

Answer 6

it can't be factored