List of symbols�

List of Symbols for the AS Course

(you need to know the equations in bold, the rest are on the formula sheet)



quantity symbol unit symbol equation(s) you find

it in

acceleration a metres per second ms-2 v = u + at

squared s = ½ at2

v2 = u2 + 2as

F = ma

 n = d sin 

o

angle between centre degrees

max and nth order

o

angle of incidence i degrees n = sin i/sin r

o

angle of refraction r degrees n = sin i/sin r

area (see also cross  metre squared m-2 P = F/A

sectional area)

change in  - -

charge Q coulombs C V = W/Q or V = E/Q

Q = It

conductance G siemens S G=I/V

G = G1 + G2..

conductivity  ohm-1 metres-1 -1 m-1 G = A/l

G =I/V

o

critical angle c degrees n = 1/sin c

cross sectional area A metres squared m2 R = l/A

(see also area)  = F/A

G = A/l

current I amps A R = V/I

P = VI , P = I2R

W = VIt

V = E -Irinternal

Q = It

G =I/V

density or D) kilograms per kgm-3  = m/V or D = m/V

metre cubed

distance between slits d metres m n = d sin 

distance/displacement s metres m s = ½ at2

v2 = u2 + 2as

v = s/t

E = Fs

electromotive force E volts V V = E -Irinternal

(emf)

energy of a photon E joules J E = hf

extension x metres m  = x/l

F = kx

quantity symbol unit symbol equation(s) you find

it in

final speed v metres per second ms-1 v = u + at

v2 = u2 + 2as

k.e. = ½ mv2

focal length f metres m P = 1/f

1/v = 1/u + 1/f

force F newtons N  = F/A

F = ma

E = Fs

P = F/A

F = kx

Impulse = Ft

F = mv/t

frequency f hertz Hz v = f x 

E = hf

f = 1/T

gravitational field g newtons per N/kg W = mg

strength kilogram

image distance v metres m 1/v = 1/u + 1/f

m = v/u

impulse newton seconds Ns Impulse = Ft

initial speed u metres per second ms-1 v = u + at

v2 = u2 + 2as

internal resistance rinternal ohms  V = E -Irinternal

kinetic energy k.e. joules J k.e. = ½ mv2

length l metres m R = l/A

G = A/l

magnification m metres m m = v/u

mass m kilograms kg F = ma

k.e. = ½ mv2

 = m/V or D = m/V

p = mv

W = mg

momentum p kilogram metre kgms-1 p = mv

per second F = mv/t

= h/p

number of bits n no unit Number of

alternatives = 2n

object distance u metres m 1/v = 1/u + 1/f

m = v/u

order of maximum n no unit n = d sin 

original length l metres m  = x/l

periodic time or T seconds s f = 1/T

period or time period

Planck's constant h joules seconds Js E = hf

quantity symbol unit symbol equation(s) you find

it in

power P dioptres D P = 1/f

power P watts W P = VI

P = E/t

P = Fv



pressure P newtons per Nm-2 P = F/A

metre squared

refractive index n no unit n = sin i/sin r

n = 1/sin c

resistance R ohms  R = V/I

P = I2 R

R = R1 + R2.. (in

series)

R = l/A

resistivity  ohm metres m R = l/A

speed (see also v metres per second ms-1 v = s/t

velocity) k.e. = ½ mv2

spring constant k newtons per Nm-1 F = kx

metre

strain  no unit  = x/l

E = 

stress  newtons per Nm-2  = F/A

metre squared E = 

time t seconds s W = VIt

Q = It

v = u + at

P = E/t

Impulse = Ft

F = mv/t

v = s/t

time period or T seconds s f = 1/T

periodic time or

period

velocity (see also v metres per second ms-1 v = s/t

speed) p = mv

voltage V volts V R = V/I

G =I/V

P = VI

W = VIt

V = E -Irinternal

V = W/Q or V = E/Q

volume V metre cubed m-3  = m/V or D = m/V

wave speed v metres per second ms-1 v = f x 

quantity symbol unit symbol equation(s) you find

it in

wavelength  metres m v = f x 

n = d sin 

= h/p



weight W newtons N W = mg

work done E joules J E = Fs

P = E/t

work done/energy W joules J V = W/Q or V = E/Q

W = VIt

Young's Modulus E newtons per Nm-2 E = 

metre squared





Note that Energy E and Work W or Work done W are all the same thing.