By conservation of energy, the kinetic energy of the body just before it hits the floor is \(m v_{i}^{2} / 2=m g h_{i}\), so its velocity is \(v_{i}=\sqrt{2 g h_{i}}\). The coefficient of restitution ...By conservation of energy, the kinetic energy of the body just before it hits the floor is \(m v_{i}^{2} / 2=m g h_{i}\), so its velocity is \(v_{i}=\sqrt{2 g h_{i}}\). The coefficient of restitution is just the square root of the ratio of the rebound height to the initial height. \({ }^{1}\)
