Kinetic Energy
Reference from the original Physics I textbook.
- Kinetic Energy
Kinetic energy is the energy associated with motion. For a nonrelativistic object of constant mass, K = ½mv², so it grows with the square of speed.
- Related Glossary Terms
Elastic Collisions↗, Energy, Inelastic Collision↗, Kinetic Energy Equation (Integral Form), Potential Energy
- Index
Chapter 4 - Inelastic Collisions
Chapter 5 - Introduction to Energy
Reviewed physics notes (1)
These corrections keep the original lesson’s purpose while fixing errors in the source edition.
- The phrase “faster the energy” has no physical meaning. — Reference 1
Glossary and deeper reading · 3 refreshers
These editorial refreshers supplement the reading. Definitions and examples are added guidance; original source wording and recorded answers remain in their original context.
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Kinetic energy
Kinetic energy is energy associated with motion relative to a chosen reference frame. For a nonrelativistic translating object it is one half of its mass times speed squared. For example, doubling a cart’s speed quadruples its translational kinetic energy when its mass stays fixed.
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Elastic collision
An elastic collision conserves the total kinetic energy of the colliding system. Total momentum is also conserved when the system has negligible net external impulse, although each object’s momentum and energy can change. For example, ideal gas atoms redistribute their speeds in elastic collisions without changing the pair’s total kinetic energy.
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Inelastic collision
An inelastic collision does not conserve the colliding system’s total kinetic energy. Momentum can still be conserved when the net external impulse is negligible, and total energy remains conserved when all stores are included. For example, carts that latch together undergo a completely inelastic collision and convert some initial kinetic energy into other forms.