Question

Two bodies begin a free fall from the same height at an interval τ sec apart. How long after the first body begins its fall will the two bodies be separated by a distance l? 

Answer 1

Answer: t = l/gτ + τ/2.

Explanation:

If the time during which the first body falls is t, then the time during which the second body falls is t - τ, and the equation of motion of both bodies takes the form