In this post, you will find a list of Formulae for O Level Physics. I have listed the formulae according to the different chapters below.
O Level Physics Formulae By Chapter
Below are a list of the formulae from various chapters. Click on the link below to go directly to the chapter you are interested in.
Weight, mass and density formulae
Work, Energy and Power Formulae
Kinematics Formulae
average speed = total distance travelled / total time taken
acceleration = (initial velocity – final velocity)/ time
If a = acceleration, u = initial velocity, v = final velocity, s = displacement, t = time, these formulae can be used when acceleration is constant:
- v = u + at
- s = 1/2(u+v)t
- v2 = u2 + 2as
- s = ut + 1/2 at2
Forces Formulae
If F = resultant force, m = mass and a = acceleration,
F = ma
Weight, Mass, Density Formulae
If W = weight, m = mass and ρ = density, g = acceleration due to gravity or gravitational field strength, V = volume
W = mg
ρ = m/ V
Moments Formulae
moment = force x perpendicular distance
Pressure Formulae
pressure = force/ Area
pressure = hρg
For hydraulic presses:
F1/A1 = F2/A2
Work, Energy and Power Formulae
Work done = Force x distance
where m = mass, g = acceleration due to gravity or gravitational field strength, v = velocity, h = height
Gravitational Potential energy (Ep) = mgh
Kinetic energy (Ek) = 1/2 mv2
Power = energy/ time = work done / time
Thermal Physics Formulae
where m = mass, c = specific heat capacity, C = heat capacity, l = specific latent heat , Δθ = temperature change, Q = change in thermal energy
Q = mcΔθ
Q = C Δθ
Q = ml
Waves Formulae
where v = velocity, f = frequency, λ = wavelength, T = period
v = fλ
f = 1/T
Light Formulae
For reflection, angle of incident = angle of reflection
For refraction where n = refractive index, i = angle of incident in vacuum or air, r = angle of refraction in medium, c is critical angle
n = sin i/ sin r
n = 1 / sin c
Sound Formulae
speed = distance travelled / time taken
Electricity Formulae
Q = It
V = W/ Q
R = ρl/A
V= IR
P = VI = I2R = V2/R = energy/ t = work done/ t
Energy = Power x t = VIt = I2Rt = (V2/R)t
For series circuits:
Current is the same everywhere in a series circuit
Total potential difference = sum of potential difference across each component
Total resistance = sum of resistance of each component
If we make use of this example of a series circuit below:
Relationship between V, I and R in series circuit
For potential difference (p.d.)
V= V1 + V2
V1 = [R1/ (R1+ R2) ]V
V2 = [R2/ (R1+ R2) ]V
For current:
I = I1 = I2
For resistance:
Rtotal = R1 + R2
For parallel circuits:
To find total current, we add them up.
When parallel, potential difference is the same
1/ (Total resistance) = 1/R1 + 1/ R2 +…
If we make use of this example of a parallel circuit below:
Relationship between V, I and R in parallel circuit
For potential difference (p.d.)
V= V1 = V2
For current:
I = I1 + I2
For resistance:
1/Rtotal = 1/R1 + 1/R2
Electromagnetic Induction
For 100% efficient transformers:
IpVp = IsVs
Ns/Np = Vs/Vp
where
Ns = number of turns in secondary coil
Vs = potential difference across secondary coil
Is = current in secondary coil
Np = number of turns in primary coil
Vp = potential difference across primary coil
Ip = current in primary coil
Learn On-demand – O Level Physics Courses
Knowing the formulae is only a part of the O Level Physics exam. We go into detail what you need to know, and how to apply the concepts in our O Level Physics courses. Find out more here.