Question

A ball is thrown horizontally and at same time another ball is dropped down from the top of a tower

1. Will both the balls reach the ground at the same time?
2. Will both strike the ground with the same velocity?

Answer 1

1- Yes, both the balls reach the ground at the same time.
The initial vertical velocity of both the balls is zero and both will cover same vertical distance under the same vertical acceleration g.
2-No.
When balls strike,their vertical velocities will be the same but horizontal velocities will be different.
Therefore, their resultant velocities will be different.