Physics / supporting

Inelastic Collision

Also known as: perfectly inelastic collision

principle

A collision in which momentum is conserved but kinetic energy is not — some energy is lost to heat, sound, or deformation. Most real-world collisions are inelastic — cars, sports impacts, and crashes all lose energy.

💡 Intuition

Two cars crashing and sticking together: they move as one object and kinetic energy is lost.

Core Idea

Momentum is always conserved in collisions; kinetic energy is not if objects deform or stick.

🔬 Example

A ball of clay hitting a wall and sticking — it doesn't bounce; the kinetic energy converts to deformation.

🎯 Why It Matters

Most real-world collisions are inelastic — cars, sports impacts, and crashes all lose energy.

⚠️ Common Confusion

Inelastic doesn't mean momentum is lost — only kinetic energy decreases.

Related Concepts

How Inelastic Collision Connects to Other Ideas

To understand inelastic collision, you should first be comfortable with conservation of momentum and kinetic energy. Once you have a solid grasp of inelastic collision, you can move on to elastic collision.

Go Deeper

Frequently Asked Questions

What is Inelastic Collision in Physics?

A collision in which momentum is conserved but kinetic energy is not — some energy is lost to heat, sound, or deformation.

Why is Inelastic Collision important?

Most real-world collisions are inelastic — cars, sports impacts, and crashes all lose energy.

What do students usually get wrong about Inelastic Collision?

Inelastic doesn't mean momentum is lost — only kinetic energy decreases.

What should I learn before Inelastic Collision?

Before studying Inelastic Collision, you should understand: conservation of momentum, kinetic energy.