I'm having some trouble figuring out how to do the following question:

Question

A ball punted vertically has a hang time of 3.65 seconds. What was its initial velocity? (I use an acceleration of -10 m/s/s)

Thanks!

Answer 1

hf=hi+vi*t-4.9t^2
0=0+vi*t-4.9t^2 solve for vi

Answer 2

Thanks so much!