Conservation of Kinetic Energy Equation
Reference from the original Physics I textbook.
- Conservation of Kinetic Energy Equation
For an elastic collision with body 2 initially at rest, using scalar speeds:
½m₁v₁ᵢ² = ½m₁v₁_f² + ½m₂v₂_f².For a general elastic collision, include the initial energy of body 2 as well: ½m₁v₁ᵢ² + ½m₂v₂ᵢ² = ½m₁v₁_f² + ½m₂v₂_f².
- Related Glossary Terms
Collision Equations, Conservation of Energy Equations, Energy
- Index
Chapter 4 - Elastic Collisions
Chapter 4 - FFR - Kinetic Energy
Reviewed physics notes (2)
These corrections keep the original lesson’s purpose while fixing errors in the source edition.
- Kinetic-energy conservation must specify an elastic collision; speeds are scalars. — Reference 1
- Adds the general conservation condition without claiming all collisions are elastic. — Reference 1
Glossary and deeper reading · 1 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.