Physics Uncovered on Instagram: "Prof. Walter Lewin’s well-known basketball–tennis ball experiment is a classic way to show how elastic collisions and momentum transfer work. When the two balls are dropped at the same time, the basketball rebounds off the ground and passes much of its momentum to the tennis ball. As a result, the tennis ball shoots upward to a height far greater than its original drop point. This dramatic demonstration highlights the conservation of both energy and momentum duri