Question

The height of an object dropped from the top of a 144-foot building is given by . How long will it take the object to hit the ground?

Answer 1

They left off the equation but we can know it's

y(t) = h₀ - g t² / 2

That's

y(t) = 144 - 16 t²

It hits the ground when

0 = 144 - 16 t²

16 t² = 144

t² = 144 / 16 = 9

t = 3 seconds

Answer: 3 seconds