A spring is a mechanical device that converts potential energy to kinetic energy. A more complex analysis of this mechanism will be examined in the following paragraphs. The first thing we need to know is how much potential and kinetic energy does it have? The length of the spring, , determines its potential energy, if a mass hangs from it then there will be no gravitational force on the mass and thus no kinetic energy. The more the spring is compressed, or stretched out, from its natural length increases.
The spring can be seen as a linear elastic object. When an external force acts on it in direction of compression or extension there will be forces acting to restore the original shape and position by resisting change.
This restoring force is known as tension T for compressing springs and compression C for extending springs which have been modeled mathematically with Hooke’s law: This equation may seem complicated but it isn’t. All we need to know is that this coefficient k determines how much energy the spring has when compressed/stretched (which depends on ). It also tells us how much work needs to be done at what distance so these are all valid units of measurement.