Two object, one of mass m and the other of mass 2m, are dropped from the top of a building. if there is no air resistance, when they hit the ground

They hit the ground at the same time

Explanation:

Mass doesn't matter in free fall. As long as they were released with the same velocity and the same height, they'll hit the ground at the same time

here we know that ball will drop down by total distance 3.2 m

so here we know that

now using kinematics

now in the same time it will cover horizontal distance of 0.75 m

so speed of the ball will be

0.11 m/s and 0.28 m/s should be correct