Elastic potential energy
When a spring is stretched, work is done, which means some energy was transferred.
This energy has to go somewhere, and so it’s transferred into the elastic potential energy store of the object.
When the tension is removed from the spring, energy is transferred from the elastic potential store, and into kinetic energy.
- If the spring has plastic behaviour, it will not fully return to its original shape when the force is removed, as not all the elastic potential energy is transferred back into kinetic energy.
- If the spring has fully elastic behaviour, it will return to its original shape because all its elastic potential energy is converted back into kinetic energy.
E=\frac12k\Delta L^2
E is the energy transferred, in joules (J )k is the spring constant, in newtons per metre (Nm^{-1} )\Delta L is the extension of the spring, in metre (m )
E=\frac12F\Delta L
E is the energy transferred, in joules (J )F is the force applied, in newtons (N )\Delta L is the extension of the spring, in metre (m )
flashcards
| Question | Answer |
|---|---|
| What happens to energy when a spring is stretched? | Work is done, transferring energy into the elastic potential energy store of the object. |
| Where does the energy in a stretched spring go when tension is removed? | Energy is transferred from the elastic potential store into kinetic energy. |
| What happens to a spring with plastic behaviour when the force is removed? | It will not fully return to its original shape, as not all the elastic potential energy is transferred back into kinetic energy. |
| What happens to a spring with fully elastic behaviour when the force is removed? | It will return to its original shape because all its elastic potential energy is converted back into kinetic energy. |
| What is the formula for elastic potential energy using the spring constant? | |
| In the formula | The spring constant, in newtons per metre ( |
| In the formula | The extension of the spring, in metre ( |
| What is the alternative formula for elastic potential energy using force? | |
| In the formula | The force applied, in newtons ( |
| What is the unit for energy | joules ( |