---
title: "Inelastic Collision — AP Physics 1 Definition & Exam Guide"
description: "An inelastic collision conserves momentum but not kinetic energy. Learn how AP Physics 1 tests it in Unit 5 and how it differs from elastic and perfectly inelastic collisions."
canonical: "https://fiveable.me/ap-physics-1-revised/key-terms/inelastic-collision"
type: "key-term"
subject: "AP Physics 1"
---

# Inelastic Collision — AP Physics 1 Definition & Exam Guide

## Definition

An inelastic collision is a type of collision where kinetic energy is not conserved. The objects involved stick together after the collision and move as one.

## Related Study Guides

- [Unit 5 FRQ (Momentum) Answers](/ap-physics-1-revised/unit-Udr75ggSrboDhyB7/unit-5-frq-momentum-answers/study-guide/3XJVcCNZveHizrmf8cQb)
- [5.4 Conservation of Linear Momentum](/ap-physics-1-revised/unit-5/conservation-linear-momentum/study-guide/k0LqYNTiudaqRa9GvvhL)

## Review

### Related Terms

- Conservation of Linear Momentum: The principle that states that the total momentum of a system remains constant if no external forces act on it.
- [Elastic Collision](/ap-physics-1-revised/key-terms/elastic-collision): A type of collision where both momentum and kinetic energy are conserved.
- Perfectly Inelastic Collision: A special case of an inelastic collision where the objects stick together and move with a common final velocity.