Formulas

average speed

average speed

average speed = distance moved/time taken

acceleration

a = (v-u)/t

relationship between final speed, initial speed, acceleration, and distance moved

v² = u²+2as

relationship between unbalanced force, mass, and acceleration

f = ma

relation between weight, mass, and gravitational fieldstrength

w = mg

relationship between power, current, and voltage

p = iv

relationship between energy transferred, current, voltage, and time

e = ivt

voltage, current, resistance

v = ir

relationship between charge, current, and time

q = it

relationship between energy transferred, charge, and voltage

e = qv

wave speed

v = f x lambda (wavelength)

frequency and time period

f = 1/t

refractive index

n = sin i x sin r

critical angle

sin c = 1/n

efficiency

efficiency = useful energy output/total energy output x 100%

Work done

W = fd

GPE

GPE = mgh

KE

KE = 1/2mv²

Power, work done, time taken

p = w/t

density

density = mass/volume

pressure

p = f/a

pressure difference

pressure difference = height x density x gravitational fieldstrength

Boyle’s law (with conditions)

For a fixed mass of gas at a constant temperature, p1v1 = p2v2

Pressure Law (with conditions)

At a constant mas and volume of gas, p1/t1 = p2/t2

orbital speed, orbital radius, time period

v = 2πr/t