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Elastic potential energy
Beginner
Energy stored in a deformed spring.
U = ½kx²A spring stores U = ½kx² when stretched or compressed by x. It is zero at the natural length and the same for compression and extension.
k = 500 N/m compressed 4 cm stores 0.4 J.
x must be measured from the natural length.
In more detail
Elastic potential energy is stored in a deformed spring or elastic material, equal to one half k x squared for a spring. It is released when the material returns to its natural shape.
Real-world uses
- Trampolines store and release elastic energy in their springs or fabric.
- Archery bows store energy in their limbs for launching arrows.
- A trampoline stores elastic potential energy in its stretched mat, which returns energy to the jumper.
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Frequently asked questions
Is elastic energy lost when a spring bounces?
In an ideal spring, no. Real springs lose some energy as heat and sound.
Does the energy depend on stretch or compression?
Either, since it depends on x squared.
How is elastic potential energy different from gravitational?
Elastic energy depends on how far a material is deformed, while gravitational energy depends on height in a gravitational field.
Related topics in Work, Energy & Power
Work–energy theorem · Potential energy · Gravitational potential energy · Conservative forces · Non-conservative forces · Force from potential energy