Solve Free Fall: Time Calculation for Rock Dropped from Tower

[Hassin]

I have this excerise to do:

A boy is standing on the tower o height h. He shot with his slingshot a rock vertically up with velocity v0, gravitational acceleration equals g. After what time t the rock has fallen?

Answer is t = (v0 + sqrt((v0)^2 + 2gh))/g
but how to get to it? Computationally and logically - what is the way of thinking step by step? ;)

I would be very grateful for quick answer!

 

[PhanthomJay]

Please review and understand the kinematic motion equations for constant acceleration. You can find them in the " intro physics formulay" thread at the top of the page, or do a web search. The derivation of these equations should be understood before memorizing and applying them.