Formulas

All formulas

Speed

Distance ÷ Time

Velocity

Displacement ÷ Time

Acceleration

Change in velocity ÷ Time

Retardation

Negative acceleration

Uniform Motion

Equal distances in equal intervals

Non-uniform Motion

Unequal distances in equal intervals

Equation of Motion 1

v = u + at

Equation of Motion 2

s = ut + ½at²

Equation of Motion 3

v² = u² + 2as

Momentum

p = m × v

Impulse

Force × Time

Impulse-Momentum

The change in momentum

Newton’s Second Law

F = m × a

Weight

W = m × g

Gravitational Force

F = G × (m1m2 / r²)

Work Done

Force × Displacement

Work Against Gravity

m × g × h

Power

Work ÷ Time

Power (alternative)

Force × Velocity

Energy

Capacity to do work

Kinetic Energy

½ m v²

Potential Energy

m g h

Mechanical Energy

K.E + P.E

Pressure

Force ÷ Area

Thrust

Force perpendicular to surface

Density

Mass ÷ Volume

Relative Density

Density of substance ÷ Density of water

Archimedes Principle Loss of weight

Buoyant force = Weight of fluid displaced

Heat

Q = m × c × ΔT

Heat Capacity

m × c

Latent Heat

Q = m × L

Principle of Calorimetry

Heat lost = Heat gained

Current

I = Q ÷ t

Potential Difference

V = W ÷ Q

Ohm’s Law

V = I × R

Resistance formula

R = ρ × (L/A)

Resistivity Constant

Depends on material

Power formula 1

P = V × I

Power formula 2

P = I²R

Power formula 3

P = V² ÷ R

Electrical Energy

P × t

Commercial Unit

kWh (kilowatt-hour)

Series Resistance

R = R1 + R2 + R3

Parallel Resistance

1/R = 1/R1 + 1/R2 + 1/R3

Series Potential

Divides according to resistance

Parallel Potential

Same across all branches

Heat Produced in Wire

H = I² R t (Joule’s Law)

Specific Resistance

Resistance × (Area ÷ Length)

Work Function

hν₀

Photon Energy

E = hν

Einstein’s Photoelectric Equation

hν = hν₀ + ½mv²max

Refractive Index

n = sin i ÷ sin r

Refractive Index (speed)

n = c ÷ v

Critical Angle

sin C = 1/n

Lens Formula

1/v – 1/u = 1/f

Magnification (lenses)

m = v/u

Power of Lens

P = 1/f (in metres)

Total Power

P = P1 + P2

Mirror Formula

1/u + 1/v = 1/f

Magnification (mirror)

Height of image ÷ Height of object

Magnification (mirror 2)

–v/u

Wave Speed

v = f × λ

Frequency

1 ÷ Time period

Numerical Aperture

n sin θ

Echo Formula

Distance = Speed × Time/2

Mechanical Advantage

Load ÷ Effort

Velocity Ratio

Distance moved by effort ÷ distance moved by load

Efficiency

(MA ÷ VR) × 100

Lever Principle

Effort × Effort arm = Load × Load arm

Transformer Equation

Vp ÷ Vs = Np ÷ Ns

Transformer Power

Input power = Output power (ideal)

Step-up Transformer

Secondary > Primary

Step-down Transformer

Primary > Secondary

Force on Charge

F = qE

Electrical Power Loss

P = I²R

Safe Fuse Rating

Power ÷ Voltage

Moment of Force

Force × Perpendicular distance

Principle of Moments

Clockwise moment = Anti-clockwise moment

Center of Gravity

Depends on symmetry and distribution

Universal Gravitational Constant

F = G(m1m2/r²)

Pressure in Fluids

hρg

Upthrust

Weight of displaced liquid

Pendulum Time Period

T = 2π √(L/g)