iGCSE CIE Triple Physics Formulaes

Formula for average speed

d / t

Average velocity

x / t

Acceleration

(v - u) / t

Weight

mg

Force

ma

Density

m / V

Hooke’s law

kx

Pressure

F / A

Fluid pressure

ρgh

Work Done

Fd

Power (using work)

W / t

Kinetic energy

½mv²

Gravitational Potential Energy (G.P.E)

mgh

Efficiency

(Pout / Pin) × 100%

Moment

Fd

Momentum

mv

Impulsive force

Δp / t

Impulse

mv - mu

Boyle's Law

P₁V₁ = P₂V₂

Thermal energy

mcT

Celsius to Kelvin conversion

C = K - 273 OR K = C + 273

Wave speed

fλ

Frequency

f = 1 / T

Refractive index (angle)

sin(i) / sin(r)

Refractive index (speed)

c / v

Refractive index (critical angle)

1 / sin(c)

Current

Q / t

Voltage (energy)

W / Q

Ohm’s Law

V=IR

Power (using Current & Voltage)

IV

Power (using current & resistance)

I²R

Energy Transferred (using current, voltage & time)

IVt (Unit J)

Energy Transferred (using power & time)

Pt (Unit J)

Total resistance in series

Rtotal = R₁ + R₂ + R₃ + …

Total resistance in parallel

1/Rtotal = 1/R₁ + 1/R₂ + …

Resistance of a wire

ρl / A (ρ=resistivity, Ohms x m, l=length, A=area)

Area of circular cross-section

A = πr²

Transformer (voltage)

Vs / Vp = Ns / Np

Transformer (current)

Vs / Vp = Is / Ip

Alpha decay equation

Beta decay equation

Gamma emission equation

Orbital speed

v = 2πr / T

Hubble Constant

H₀ = 2.2 × 10⁻¹⁸ s⁻¹

Hubble’s Law

d / v = 1 / H₀