1. The problem statement, all variables and given/known data Two balls of masses m1& m2 are placed on different platforms, which are subjected to springs of same force constant and same compression. (springs are under platforms, basically like launch pads to fire the balls into the air). When the platform of first ball is released, m1 rises to maximum height in 4 seconds. Find the time in which the other ball will rise to it's maximum height T1 = 4 s 2. Relevant equations Spring PE = 1/2 kx2 3. The attempt at a solution I tried solving the problem neglecting the time taken for the spring restore it's length,(only considering time of flight, after ball loses contact with platform) But the answer doesn't seem to match. I'm unable to calculate time taken for spring to restore it's length. I hope someone can give me some direction on how to proceed.