A must-have for chemistry and physics classrooms!
Explore polymer chemistry and elastic/inelastic collisions, coefficient of restitution, and even kinetic energy with an unusual set of rubber balls. They look identical, they feel identical… but they behave very differently upon impact with a solid surface. One ball will bounce very high (Happy); the other ball will not bounce (Sad)! The two balls have virtually the same density, mass, texture, and appearance. They respond differently upon impact because they are manufactured with different types of rubber. The Happy, or elastic, ball is made of Polychloroprene, or neoprene rubber. The Sad, or inelastic, ball is made of Polynorbornene, or norsorex rubber. While the Happy Ball stores very little energy in collisions and bounces well, the Sad Ball stores and transforms most of its kinetic energy and doesn’t bounce. Whereas the Happy Ball has a restitution of elasticity of about 53%, the Sad Ball’s restitution is about 3%. Due to their composition, even allows for study of momentum, since the Happy Ball also rolls faster than the Sad Ball.
Included:
- One Happy and one Sad Ball, each ~1″ in diameter.
- The happy ball also rolls faster than the sad ball
Disciplinary Core Ideas Targeted:
MS-PS1.A: Structure and Properties of Matter
MS-PS3.A: Definitions of Energy
HS-PS1.A: Structure and Properties of Matter
HS-PS3.A: Definitions of Energy
HS-PS3.B: Conservation of Energy and Energy Transfer
