Answer to Question #97085 in Mechanics | Relativity for lucas

Question

You're on a rooftop and you throw a ball downward below and another upward. The second ball, after rising, falls and strikes the ground below. If air resistance can be ignored, and if your downward and upward speeds are the same, how do you think the speeds of the balls compare upon striking the ground. use energy considerations when answering.

Answer 1

From the conserrvation of energy the speeds of the balls will be equal:

$$E_i=E_f=mgh+0.5mv^2$$