🔋 3. Energy & Work

Work is done when a force moves an object through a distance: W = Fd.

Kinetic energy is the energy of motion: KE = ½mv².

Gravitational potential energy is the energy of position: GPE = mgh.

The principle of conservation of energy: energy cannot be created or destroyed.

Power is the rate of doing work: P = W/t = Fv.

Efficiency = useful output energy / total input energy × 100%.

Elastic potential energy is stored in stretched or compressed springs: EPE = ½kx².

Work-energy principle: work done = change in kinetic energy.