Two blocks move along a linear path on a nearly frictionless air track. One block, of mass 0.100 kg, initially moves to the right at a speed of 5.00 m/s, while the second block, of mass 0.200 kg, is initially to the left of the first block and moving to the right at 7.00 m/s. Find the final velocities of the blocks, assuming the collision is elastic.

area of focus

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.