Elastic Potential Energy

This lesson covers the elastic potential energy (EPE) store and the equation $EPE = \frac{1}{2}ke^2$EPE=21​ke2, as required by the Edexcel GCSE Combined Science specification (1SC0). You will also learn about Hooke's law and how springs store and release energy.

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What Is Elastic Potential Energy?

Elastic potential energy (EPE) is the energy stored in an object when it is stretched or compressed. When the force is removed and the object returns to its original shape, the stored energy is released.

Examples of objects that store EPE:

• A stretched spring
• A compressed spring
• A stretched rubber band
• A bent diving board
• A drawn bow (archery)

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Hooke's Law

Before studying EPE, you need to understand Hooke's law, which describes how springs behave when a force is applied.

$F = ke$F=ke

where:

• F = force applied in newtons (N)
• k = spring constant in newtons per metre (N/m)
• e = extension (or compression) in metres (m)

Quantity	Unit	Symbol
Force	newton	N
Spring constant	newtons per metre	N/m
Extension	metre	m