The Happy & Sad Bounce/No Bounce Ball Set includes two black rubber balls, each 1-3/8″ in diameter, which appear to be identical in appearance and mass but are actually manufactured from different types of rubber. When dropped on a hard surface from an equal height, the “happy” ball bounces high and the “sad” ball barely bounces at all. The happy ball also rolls faster than the sad ball. These balls provide an interesting and memorable demonstration for studying elasticity, kinetic energy, and polymer composition.

• Two black rubber balls, 1-3/8″ in diameter, appear identical in appearance and mass
• Balls are actually manufactured from different types of rubber
• Demonstrate and study elasticity, kinetic energy, and polymer composition