This document contains a summary of key physics formulas and concepts for 'O' Level Physics. It includes: 1) Definitions of base SI units for common physical quantities like mass, length, time, current, temperature, and amount of substance. 2) Formulas for measurements, kinematics, dynamics, work, energy, power, gas laws, heat, electromagnetism, optics, and electricity. 3) Descriptions of important physics principles like Newton's laws of motion, conservation of energy, Ohm's law, Kirchhoff's laws, and more.

1. ‘O’ Level Physics Formula Sheet
Measurements Principle of Moment For a body in rotational
Base SI Units Σ Anticlockwise Moment equilibrium,
Kg SI Unit for mass: Kilogram = Σ Clockwise Moment Sum of ACW Moment = sum of
m SI Unit for length: metre CW Moment
Pressure
F
s SI Unit for time: second
=
A SI Unit for current: Ampere Pressure P = Pressure
A
K SI Unit for Temperature: Kelvin F = Force over area, A
mol SI Unit for Amount of substance: molar A = Area
Number Prefix Pressure of liquid P = Pressure
n (10-9) nano column ρ = density,
µ (10-6) micro P = hρg h = height of liquid column
m (10-3) milli
g = gravitational field strength.
c (10-2) centi
d (10-1) deci Energy, Work and Power
K (103) Kilo Work Done W = work done
M (106) Mega W = Fd F= force
d= distance in direction of force
Kinematics Power Work done per unit time, t
∆d = total distance travelled (area under
1
Average Speed P = W/t = Fv
= mv 2
s = ∆d / ∆t speed-time graph) Kinetic Energy Ek = Kinetic Energy
2
∆x = total displacement m = mass
Average Velocity ∆t = total time taken v = velocity
v = ∆x/∆t ∆v = change in velocity Gravitational Potential g = gravity =9.81 m/s
Acceleration Velocity (slope of displacement-time graph) Energy h = height
a = ∆v/∆t Acceleration (slope of velocity-time graph) Ep = mgh m = mass
v = u + at u = initial velocity Conservation of Energy E1 = Total Energy Before
x = ut + ½ at2 v = final velocity E1 = E2 E2 = Total Energy After
v2 = u2 + 2ax t = time
Energy cannot be created or
a = acceleration destroyed. It can only be
vfree fall = �2ℎ
x = displacement
transformed or converted into other
h = height
forms.
g = gravitational constant = 9.81 m/s2
Dynamics Kinetic Model of Matter
⃑
∑ = 0 at equilibrium
Ideal Gas Law P = pressure of fixed mass of gas
Newton’s First Law A body continues to stay in its state
PV ∞ T V = volume occupies by fixed mass
of rest or uniform motion in a
of gas
straight line as long as there is no
T = Temperature of gas
net force/moment acting on the
P1V1 = P2V2 Subscript 1 = initial state
body.
Subscript 2 = final state
Newton’s Second Law The acceleration of an object is
F= ma directly proportional to the net force Thermal Properties of Matter
acting on it and inversely Specific Heat Capacity c = Specific heat capacity (Energy
proportional to its mass. E = m c ∆T required to raise the temperature of
Newton’s Third Law For every force object A acts 1kg of the object by 1 °C)
on object B, object B will exert an m = mass
equal and opposite ∆T = change in temperature.
force on object A giving rise to Latent Heat Lfusion = latent heat of fusion (Energy
Reaction/Normal Forces For melting, required to change 1kg of solid to
Resolving forces Fvertical Fr E = m Lfusion liquid at the constant temp)
Fhorizontal = Fr cos Ө Lvaporization = latent heat of
Fvertical = Fr sin Ө Ө Fhorizontal For boiling, vaporization (Energy required to
E = m Lvaporization change 1kg of liquid to gas at the
Mass, Weight, Density constant temp)
Weight w = Weight m = mass
w = mg m = mass General Wave Properties
m
g = gravitational field strength
ρ=
Wave Velocity v = velocity of a wave
ρ = density
V
Density
v=fλ f = frequency
m = mass
λ = wavelength
1
V = volume
Wave frequency
T
Turning effect of Force f= T = Period
d = ⊥ distance from force to pivot
Moment of Force M = Moment f = frequency
M=Fd F = force
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2. ‘O’ Level Physics Formula Sheet
Light Practical Electricity
Law of Reflection Normal Electric Power P = Power
Өi = Өr V = voltage
2
Өi Өr P = VI = V2/R = I R R = resistance
Өi = angle of incidence I = current
Өr= angle of reflection Electrical Energy E = energy output
Snell’s Law (refraction) E = Pt = (VI)t P = power
Normal
t = time
n1Sin Өi = n2Sin Өr Өi n1 = refractive index 1 V = voltage
I = current
Өi = angle of incidence Electromagnetism
Vp Np
Өr
=
Өr = angle of refraction Transformer V = voltage
Vs Ns
n2 = refractive index 2
N = number of coils
n2
Critical angle I = current
sin =
Normal
n1
(ideal transformer) Subscript p = primary coil
n1 = refractive index 1 VPIP = VsIs Subscript s = secondary coil
Өc
Right hand grip
(special case of Snell’s
law where Өr = 90°) n2 = refractive index 2
c
=
v
Refractive Index c = speed of light in vacuum.
v = speed of light in medium
Higher reflective index of a
medium means light travel slower
(n of air ≈ 1)
hi di
in the medium
= =
Magnification M = magnification
ho do
h = height
d = distance from lens
Subscript i = image Fleming’s Right Hand
Subscript o = object Rule
Current of Electricity
Current Current = rate of flow of charges
I = Q / ∆t Q = Charge
t=time
Ohm’s Law V = voltage,
Resistance R = resistance
R=V/I I = current
Resistance of a wire ρ = resistivity Fleming’s Left Hand
R = ρL/A L = length of wire Rule
A = cross sectional area
D.C. Circuits
∑ Iin = Sum of current going into a
Kirchoff’s 1st Law Conservation of charges.
� Iin = � Iout
∑ Iout = Sum of current going out
junction
∑ V = Sum of potential difference V
of a junction
Kirchoff’s 2nd Law
� V = E. M. F
across all components in a circuit
E.M.F = Voltage supplied by the
power supply.
Prepared by etuitionx
Resistance in Series (http:/physictuition.blogspot.com)
I
R1 R2 R3
Rtotal = R1 + R2 + R3
1 1 1 1
Resistance in Parallel V
= + +
R total R1 R 2 R 3
R1
R2 References
1. PHYSICS Ordinary Level (Syllabus 5058)
R3
2. Education Haven (http://matchtutor.com.sg)
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