Momentum Transfer
#Presented by Vishal
Introduction
#Momentum transfer is a fundamental concept in physics that describes how the motion of one object can be passed on to another during a collision. When two objects collide, the total momentum of the system is conserved — meaning it neither increases nor decreases, only redistributes between the objects involved.
In this demonstration, a large ball and a small tennis ball are stacked together and dropped from the same height. The experiment produces a striking and counterintuitive result: the tennis ball shoots upward to several times the original drop height. This vivid outcome makes Newton's laws of motion and the conservation of momentum immediately tangible, helping students connect abstract equations to real, observable behaviour.
Precautions
#Stand clear of the area directly above the drop point — the tennis ball can bounce very high, sometimes exceeding three times the drop height, and may strike bystanders. Perform the demonstration in an open space with sufficient overhead clearance. Keep observers a safe distance to the side.
Materials Required
#- A large ball (basketball or football)
- A tennis ball
Science Behind It
#When both balls are dropped together, they fall at the same speed due to gravity. The large ball hits the ground first and bounces back up, while the tennis ball is still moving downward. At the moment they collide, the large ball is moving up and the small ball is moving down — they meet in a brief, nearly elastic collision.
Because the large ball is much heavier, it barely loses speed in the collision. By conservation of momentum, nearly all of its upward momentum is transferred to the lighter tennis ball. The small ball then launches upward with a velocity far greater than the original drop speed, reaching a height well beyond where it started. The ratio of the masses determines how high the ball flies, making this a vivid and memorable illustration of momentum conservation.