Formula Sheet Physics O Levels
by Umar Danish The City School Okara.
1 Motion, forces and energy
1.1 Physical Quantities
H2=P2+B2 (Pythagoras Theorem for vector resultant calculation)
1.2 Motion
Speed = distance/time
Velocity = displacement/time
Average Speed = total distance travelled/total time taken
Acceleration = change in velocity/change in time
1.3 Mass and weight
Gravitational field strength = weight/mass
1.4 Density
Density = mass/volume
1.5 Forces
resultant force = mass × acceleration
spring constant = force/extension
moment = force × perpendicular distance from the pivot
1.6 Momentum
Momentum = mass x velocity
Impulse = force x time
Impulse = FΔt = Δ(mv)
resultant force = change in momentum/time taken
All formulas provided by Cambridge in Official syllabus for O Levels 2023-2025 are included.
1.7 Work Energy and Power
Kinetic energy = mass x velocity2
Gravitational Potential Energy = mass x gravitational field strength x height
work done = force × distance moved in the direction of the force
(%) efficiency = (useful energy output)/(total energy input) ( × 100%)
(%) efficiency = (useful power output)/(total power input) ( × 100%)
power = work done x time taken
power = energy transferred time taken
1.8 Pressure
pressure = force/area
change in pressure in liquids= density × gravitational field strength × change in height
2 Thermal Physics
2.1 Kinetic particle model of matter
Pressure1xVolume1 = Pressure2xVolume2
2.2 Thermal properties and temperature
T (in K) = θ (in °C) + 273
specific heat capacity = change in energy/mass × change in temperature
3 Waves
3.1 General properties of waves
Wave speed = frequency × wavelength
3.2 Light
n = sin I / sin r
n = 1 / sin c
linear magnification = image length/object length
All formulas provided by Cambridge in Official syllabus for O Levels 2023-2025 are included.
4 Electricity and Magnetism
4.2 Electrical quantities
electric current = charge/time
e.m.f. = work done (by a source)/charge
p.d. = work done (on a component)/charge
resistance = p.d/current
4.3 Electrical Circuits
Resistance in Series: R = R1 + R2 + R3
1
1
1
1
Resistance in Parallel: 𝑅 = 𝑅1 + 𝑅2 + 𝑅3
Voltage in Series: Vin = V1 + V2 + V3
Voltage in Parallel: Vin = V1 = V2 = V3
Current in Series: Iin= I1 = I2 = I3
Current in Parallel: Iin = I1 + I2 + I3
Two resistors used as potential dividers: R1/R2 = V1/V2
4.4 Practical Electricity
power = current × voltage
energy = current × voltage × time
4.5 Electromagnetism
For transformer calculations: VP/Vs=Np/NS where P and S refer to primary and secondary.
For oscilloscope, volts = no. of divisions x y-gain
& Time period = no. of divisions x TBS
6 Space Physics
6.1 Earth and the Solar System
Average orbital speed = 2πr / T
All formulas provided by Cambridge in Official syllabus for O Levels 2023-2025 are included.