Question

You are on a rooftop and you throw one ball downward to the ground below and another upward both with the same initial speed. The second ball, after rising falls and also strikes the ground. If air resistance can be neglected what will be ratio of the speeds of the balls upon striking the ground?

Answer 1

If ignoring resistance, then both ball reach the ground at the same speed , ifa their is no air resistance, then energy at the ball is conserved, you have given the same initial kinetic energy. Which depend only on the speed and not its direction.