056 – Passing the momentum

Bump with three coins  

Introduction to:

Conservation of momentum, elastic collision, momentum transfer, central collision.  

Material:  

Three identical coins  

Instructions:  

• place two coins directly next to each other so that they touch 
• place the third coin in a straight line with the two coins, 1-2 coin diameters apart  
• flick the third coin centrally against the others with your finger  

Observation:  

• The bumping coin and the middle coin remain still.  
• The front coin is flicked away.  

Tip:  

The most difficult part is making the coins bump together centrally. Possibly use two smooth pencils as a rail!