Work out coefficient of restitution instantly with clear inputs, formula shown and shareable results.
The coefficient of restitution is the ratio of rebound speed to impact speed, and since drop speed goes as the square root of height, it is the square root of the height ratio. Dropping from 1.5 m and bouncing to 0.9 m gives e = 0.775, retaining 60% of the energy. A value of 1 would be perfectly elastic and 0 a dead drop.
From heights
e = sqrt(rebound height / drop height)
Energy retained
fraction = e^2 = h2 / h1
About 0.85 for a superball, 0.75 for a basketball, 0.6 for a tennis ball and near 0.1 for a beanbag.
Because energy goes with speed squared, so a restitution of 0.8 keeps 64% of the energy.