State that energy may be stored as kinetic, gravitational potential, chemical, elastic (strain), nuclear, electrostatic and internal (thermal)

Topic 1.7.1 – Energy

Learning Objective

State that energy may be stored as kinetic, gravitational potential, chemical, elastic (strain), nuclear, electrostatic and internal (thermal) energy.

Forms of Stored Energy

• Kinetic Energy – energy of motion.
• Gravitational Potential Energy – energy stored due to an object's position in a gravitational field.
• Chemical Energy – energy stored in chemical bonds.
• Elastic (Strain) Energy – energy stored when a material is deformed (stretched or compressed).
• Nuclear Energy – energy stored in the nucleus of an atom.
• Electrostatic Energy – energy stored due to the separation of electric charges.
• Internal (Thermal) Energy – energy associated with the random motion of particles within a substance.

Key Equations

The following equations describe the quantitative relationship for each form of stored energy.

• Kinetic Energy: \$E_k = \frac{1}{2}mv^{2}\$
• Gravitational Potential Energy: \$E_g = mgh\$
• Elastic (Strain) Energy (spring): \$E_e = \frac{1}{2}kx^{2}\$
• Chemical Energy: represented by the change in enthalpy, \$\Delta H\$ (energy released or absorbed in a reaction).
• Nuclear Energy (mass–energy equivalence): \$E_n = \Delta mc^{2}\$
• Electrostatic Potential Energy (point charges): \$E{es} = \frac{k\,q{1}q_{2}}{r}\$
• Internal (Thermal) Energy (ideal gas, per mole): \$E_{th} = \frac{3}{2}nRT\$

Summary Table

Conceptual Connections

1. All forms of stored energy can be transformed into other forms, obeying the principle of conservation of energy.
2. In many practical situations, more than one type of stored energy is present simultaneously (e.g., a roller‑coaster car has both kinetic and gravitational potential energy).
3. Understanding the storage mechanism helps predict how energy will be released or transferred in a system.