Table of Contents
Additional Common IGCSE Physics Equations #
Power Equation: #
Where:
- P = power (W or J/s)
- E = energy (J)
- t = time (s)
Gravitational Potential Energy: #
GPE = m × g × h
Where:
- GPE = gravitational potential energy (J)
- m = mass (kg)
- g = gravitational field strength (9.81 N/kg)
- h = height (m)
Ohm’s Law: #
Where:
- V = voltage (V)
- I = current (A)
- R = resistance (Ω)
Electrical Power: #
P = V × I
Where:
- P = power (W)
- V = voltage (V)
- I = current (A)
Heat Energy: #
Q = m × c × ΔT
Where:
- Q = heat energy (J)
- m = mass (kg)
- c = specific heat capacity (J/kg°C)
- ΔT = temperature change (°C)
Example: #
2 kg of water (c = 4200 J/kg°C) is heated by 10°C.
Heat Energy = 2 × 4200 × 10 = 84,000 J
Wave Speed: #
v = f × λ
Where:
- v = wave speed (m/s)
- f = frequency (Hz)
- λ = wavelength (m)
Efficiency: #
Where:
- Efficiency is expressed as a percentage (%)
- Both energies must be in the same unit (usually Joules)
Example: #
A machine has input energy of 1000 J and useful output of 800 J.
Efficiency = (800 ÷ 1000) × 100 = 80%
