Three spherical balls having mass m₁, m₂ and m₃ are placed one on top of another with their centre of masses aligned as shown in the figure below. These balls are dropped together from height H . The radii of balls are negligibly small in comparison with height H . The heights to which the masses will rebound is expressed as H_r= H . Assuming that all collisions (including the collision between m₁ and the floor) are