- When a spring is stretched or compressed by a force, work is done by the spring
- Work done is the transfer of energy
- The energy is transferred to its elastic potential energy store
- Elastic potential energy is defined as:
The energy stored in an elastic object when work is done on the object
- Provided the spring is not inelastically deformed (i.e has not exceeded its limit of proportionality, the work done on the spring and its elastic potential energy stored are equal
- The work done, or the elastic potential energy stored, while stretching or compressing a spring can be calculated using the equation:
Ee = ½ × k × e2
- Ee = elastic potential energy in joules (J)
- k = spring constant in newtons per metre (N/m)
- e = extension in metres (m)
- This equation is only for springs that have not been stretched beyond their limit of proportionality
- e2 means that if the extension is doubled then the work done is quadrupled (22 = 4)
A mass is attached to the bottom of a hanging spring with a spring constant k and 0.2 J of work is done to stretch it by 4.5 cm.
Calculate the spring constant, k for this spring.
Remember the work done is the extension, e squared (e2)!