This simulation models a system in which both momentum and mechanical energy are conserved. Two balls are dropped either side-by side or in a stacked position with initial velocity of zero. Observe how the behaviors of the two balls change with the ratio of their masses Ma/Mb. Can you explain the rebound height of the red ball using concepts of the conservation of momentum during perfectly elastic collisions and the conservation of mechanical energy?(The long rectangular box on the right displays the balls at ⅓ of their original scale.)

此程式模擬系統為遵守動量與能量守恆下，有兩顆球初速為零自由落下，兩顆球於等高處或堆疊落下時的運動，請觀察兩球質量比(ratio=Ma/Mb)不同時，兩球的運動行為，你可以運用你對完全彈性碰撞時兩球動量與能量間的轉換來解釋紅色球的彈跳高度嗎? (右方長方框是為1/3縮圖)