Forces and Energy Changes: Energy Stored in a Stretched Spring

Forces and Energy Changes: Energy Stored in a Stretched Spring

  • Understanding the concept of “energy stored in a stretched spring” requires knowledge about forces, potential energy, and Hooke’s Law.

  • Hooke’s Law states that the extension of a spring is directly proportional to the force applied, provided the limit of proportionality (elastic limit) is not exceeded. The equation for Hooke’s law is F = kx, where “F” represents force, “k” signifies the spring constant, and “x” corresponds to the extension from the spring’s original length.

  • When a spring is stretched or compressed, it stores potential energy. This type of potential energy is referred to as Elastic Potential Energy.

  • The formula for calculating Elastic Potential Energy is 1/2 kx². Here, “k” is the spring constant (a measure of stiffness), and “x” stands for the amount of displacement or deformation.

  • When a spring is stretched, the energy used in stretching is stored as potential energy. When the spring is released, this energy is transformed into kinetic energy.

  • The spring constant value “k” differs depending on the rigidity of the spring, with stiffer springs having higher k values.

  • If a spring is stretched beyond its limit of proportionality (elastic limit), it will become permanently deformed. When this occurs, the spring will not return to its original length and its stored energy will be lost as heat due to the increased internal friction.

  • The area under a force - extension graph is equal to the work done on the spring or the elastic potential energy stored in the spring.

  • Remember that energy conservation applies to springs as well: the work done on stretching or compressing the spring is equal to the increase in its elastic potential energy.

  • Real-life applications of this concept include trampolines, car suspensions, and bungee cords, which all utilise the storage and release of elastic potential energy to function.

  • This topic links to others in physics, such as energy transfers and momentum, where the potential energy in a system can be converted into other forms of energy.