# physics - all formulas

ALL THE FORMULAS NEEDED FOR IGCSE SCIENCE - PHYSICS

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• Created by: stuDYING
• Created on: 18-01-10 15:07

## FORCES & MOTION

AVERAGE SPEED = distance moved / time taken

SPEED = distance / time

ACCELERATION = change in velocity / time taken
a = (v - u) / t

speed = m/s
distance = metres
time = seconds
final speed & starting speed = m/s

FORCE = mass x acceleration

WEIGHT = mass x gravity
force = newtons
mass = kg
acceleration = m/s/s

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## ELECTRICITY

POWER = current (I) x voltage (V)
power = watts (W)
voltage = volts (V)
current = amperes (A)

ENERGY TRANSFERRED = I x V x t (P x t)

VOLTAGE = I x resistance
resistance = ohms

charge (Q) = current x time
charge= coulomb (C)

POTENTIAL DIFFERENCE = energy transferred / charge
energy = Joules

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## WAVES

wave speed (v) = frequency x wavelength
wave speed = m/s
frequency = hertz (Hz)
wavelength = m

frequency = 1 / time period

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## LIGHT AND SOUND / ENERGY TRANSFER

n (refractive index) = sin i / sin r

sin c (critical angle) = 1 / n

ENERGY TRANSFER
efficiency = useful energy output / total energy output x 100

WORK AND POWER
work = force x distance
power = work done / time taken
gravitational potential energy (GPE) = m x g x height

kinetic energy = 1/2 x mass x velocity (squared)

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## DENSITY AND PRESSURE

density = mass / volume

pressure = force,/ area

P1V1 = P2V2

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