Kinetic and Gravitational Potential Energy

This lesson covers the equations for kinetic energy (KE) and gravitational potential energy (GPE) as required by the Edexcel GCSE Physics specification (1PH0), Topic 3: Conservation of Energy. You need to be able to use, rearrange and apply these equations, and understand how energy is converted between these two stores.

---

Kinetic Energy (KE)

Kinetic energy is the energy stored in a moving object. The faster an object moves, and the greater its mass, the more kinetic energy it has.

The Equation

$KE = \frac{1}{2} m v^2$KE=21​mv2

Where:

• KE = kinetic energy (joules, J)
• m = mass (kilograms, kg)
• v = speed (metres per second, m/s)

Key Points About the KE Equation

• KE depends on speed squared — if you double the speed, KE increases by a factor of four (2² = 4).
• If you treble the speed, KE increases by a factor of nine (3² = 9).
• KE depends linearly on mass — double the mass, double the KE.