Mechanics
Velocity
v = u + at Distance (uniform acceleration)
s = ut + ½at² Velocity–distance relation
v² = u² + 2as Momentum
p = mv Newton’s second law
F = ma Weight
W = mg Work done
W = Fs Kinetic energy
KE = ½mv² Potential energy
PE = mgh Power
P = W/t = Fv Force of gravity
F = GMm/r² Hooke’s law
F = ke Pressure
P = F/A Pressure in a liquid
P = ρgh Simple harmonic motion period
T = 2π√(m/k) Heat
Heat quantity
Q = mcΔθ m = mass, c = specific heat capacity
Latent heat
Q = mL Linear expansion
Δl = α l₀ Δθ Volume expansion
ΔV = γ V₀ Δθ Gas laws (general)
PV/T = constant Ideal gas equation
PV = nRT Waves and Light
Wave equation
v = fλ Refractive index
n = sin i / sin r Refractive index (speed)
n = c/v Critical angle
sin C = 1/n Lens formula
1/f = 1/u + 1/v Magnification
m = v/u = hᵢ/hₒ Power of a lens
P = 1/f (in metres) Frequency of a string
f₀ = (1/2L)√(T/μ) Electricity and Modern Physics
Ohm’s law
V = IR Resistance in series
R = R₁ + R₂ + R₃ Resistance in parallel
1/R = 1/R₁ + 1/R₂ + 1/R₃ Electric power
P = IV = I²R = V²/R Electrical energy
E = Pt = IVt Coulomb’s law
F = kQ₁Q₂/r² Capacitance
C = Q/V Energy in a capacitor
E = ½CV² Einstein’s photoelectric equation
E = hf = W₀ + KEₘₐₓ Mass–energy relation
E = mc² Radioactive decay
N = N₀e^(−λt) Test yourself on Physics
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