Collisions: Elastic and Inelastic
Learning Objectives
- Students will understand elastic and inelastic collisions
- Students will apply momentum conservation in collisions
- Students will analyze energy changes in different types of collisions
Core Concepts
- Elastic collision: kinetic energy conserved
- Inelastic collision: kinetic energy not conserved (becomes heat, sound, deformation)
- Momentum is conserved in all collisions
Formulas
$$p_{before} = p_{after}$$
Momentum conservation in any collision
$$KE_{before} = KE_{after}$$
Kinetic energy conservation in elastic collisions
$$m_1 v_{1i} + m_2 v_{2i} = m_1 v_{1f} + m_2 v_{2f}$$
Momentum conservation for two objects
Interesting Fact
Newton's cradle demonstrates elastic collisions very clearly
Key Scientist
Christian Huygens
Early study of elastic collisions and momentum conservation
Philosophy
The distinction between elastic and inelastic collisions reflects how outcomes depend on the nature of interaction—material properties matter fundamentally.
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