Question

if a ball is traveling with constant velocity suddenly the ball is go down and reach to floor the distance between the top and bottom position is 1.5m .what is velocity of the ball if the ball is go down with respect to gravity due to depth?

Answer 1

I'm assuming the ball is thrown with the same effort in both cases or there is no answering this; they won't hit the ground at the same time if thrown at the same time though.

Conservation of energy would have me suggest it makes no difference.

Assuming the throwing speed - kinetic energy to be completely correct - and the height at which the ball is released don't differ both cases result in the same net kinetic energy at impact on ground level and the same velocity.

This is my thinking;

Thrown upwards all kinetic energy is first transformed into potential energy, and subsequently back to kinetic until the ground level.

Thrown downward the kinetic energy is increased with the same net amount - from the throwing height to the floor - as in the "upward" case.

If my interpretation is correct the coincidental impact is a red herring; it makes no difference for the energy and hence velocity.