O Level Physics Formula Sheet

‘O’ Level Physics Formula Sheet Measurements Base SI Units Kg m s A K mol Number Prefix n (10-9) µ (10-6) m (10-3) c (10-2) d (10-1) K (103) M (106)

SI Unit for mass: Kilogram SI Unit for length: metre SI Unit for time: second SI Unit for current: Ampere SI Unit for Temperature: Kelvin SI Unit for Amount of substance: molar nano micro milli centi deci Kilo Mega

Kinematics

Dynamics

Newton’s Third Law

Resolving forces Fhorizontal = Fr cos Ө Fvertical = Fr sin Ө

A body continues to stay in its state of rest or uniform motion in a straight line as long as there is no net force/moment acting on the body. The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. For every force object A acts on object B, object B will exert an equal and opposite force on object A giving rise to Reaction/Normal Forces Fr Fvertical Ө

Fhorizontal

Mass, Weight, Density w = Weight m = mass g = gravitational field strength ρ = density m = mass V = volume

Weight w = mg Density m ρ= V

Turning effect of Force

Moment of Force M=Fd

1

P = Pressure F = Force over area, A A = Area P = Pressure ρ = density, h = height of liquid column g = gravitational field strength.

Energy, Work and Power

∆d = total distance travelled (area under speed-time graph) ∆x = total displacement Average Velocity ∆t = total time taken ∆v = change in velocity v = ∆x/∆t Velocity (slope of displacement-time graph) Acceleration Acceleration (slope of velocity-time graph) a = ∆v/∆t v = u + at u = initial velocity v = final velocity x = ut + ½ at2 t = time v2 = u2 + 2ax a = acceleration x = displacement h = height vfree fall = �2𝑔ℎ g = gravitational constant = 9.81 m/s2

Newton’s Second Law F= ma

Pressure Pressure F 𝐏= A Pressure of liquid column P = hρg

Work Done W = Fd

Average Speed s = ∆d / ∆t

Newton’s First Law ∑ 𝐹⃑= 0 at equilibrium

For a body in rotational Principle of Moment Σ Anticlockwise Moment equilibrium, = Σ Clockwise Moment Sum of ACW Moment = sum of CW Moment

M = Moment F = force d = ⊥ distance from force to pivot

Power P = W/t = Fv Kinetic Energy 1 𝐄𝐤 = mv 2 2 Gravitational Potential Energy Ep = mgh Conservation of Energy E1 = E2

W = work done F= force d= distance in direction of force Work done per unit time, t Ek = Kinetic Energy m = mass v = velocity g = gravity =9.81 m/s h = height m = mass E1 = Total Energy Before E2 = Total Energy After Energy cannot be created or destroyed. It can only be transformed or converted into other forms.

Kinetic Model of Matter Ideal Gas Law PV ∞ T P1V1 = P2V2

P = pressure of fixed mass of gas V = volume occupies by fixed mass of gas T = Temperature of gas Subscript 1 = initial state Subscript 2 = final state

Thermal Properties of Matter Specific Heat Capacity c = Specific heat capacity (Energy required to raise the temperature of E = m c ∆T 1kg of the object by 1 °C) m = mass ∆T = change in temperature. Lfusion = latent heat of fusion (Energy Latent Heat required to change 1kg of solid to For melting, liquid at the constant temp) E = m Lfusion Lvaporization = latent heat of vaporization (Energy required to For boiling, change 1kg of liquid to gas at the E = m Lvaporization constant temp) m = mass

General Wave Properties Wave Velocity v=fλ Wave frequency 1 f= T

v = velocity of a wave f = frequency λ = wavelength T = Period f = frequency

http://physictuition.blogspot.com

‘O’ Level Physics Formula Sheet Light

Practical Electricity

Law of Reflection Өi = Өr

Normal

Electric Power

Өi

2 P = VI = V2/R = I R

Өi = angle of incidence Өr= angle of reflection Snell’s Law (refraction)

Normal

n1Sin Өi = n2Sin Өr

Өi

Өi = angle of incidence Өr = angle of refraction Critical angle

Өr

Electrical Energy E = Pt = (VI)t

n1 = refractive index 1

Electromagnetism

Өr n2 = refractive index 2 Normal

n2 sin 𝚯𝐜 = n1

Өc

(special case of Snell’s law where Өr = 90°)

n1 = refractive index 1

(n of air ≈ 1) Magnification hi di 𝐌= = ho do

Transformer Vp Np = Vs Ns (ideal transformer) VPIP = VsIs Right hand grip

V = voltage N = number of coils I = current Subscript p = primary coil Subscript s = secondary coil

n2 = refractive index 2 c = speed of light in vacuum. v = speed of light in medium Higher reflective index of a medium means light travel slower in the medium M = magnification h = height d = distance from lens Subscript i = image Subscript o = object

Refractive Index c 𝐧= v

P = Power V = voltage R = resistance I = current E = energy output P = power t = time V = voltage I = current

Fleming’s Right Hand Rule

Current of Electricity Current = rate of flow of charges Q = Charge t=time V = voltage, R = resistance I = current ρ = resistivity L = length of wire A = cross sectional area

Current I = Q / ∆t Ohm’s Law Resistance R=V/I Resistance of a wire R = ρL/A

Fleming’s Left Hand Rule

D.C. Circuits Kirchoff’s 1st Law � Iin = � Iout

Kirchoff’s 2nd Law � V = E. M. F

Conservation of charges. ∑ Iin = Sum of current going into a junction ∑ Iout = Sum of current going out of a junction ∑ V = Sum of potential difference V across all components in a circuit E.M.F = Voltage supplied by the power supply.

Resistance in Series Rtotal = R1 + R2 + R3 Resistance in Parallel 1 1 1 1 = + + R total R1 R 2 R 3

2

Prepared by etuitionx (http:/physictuition.blogspot.com)

I R1

R2

R3

V R1 R2 R3

References

1. PHYSICS Ordinary Level (Syllabus 5058) 2. Education Haven (http://matchtutor.com.sg) http://physictuition.blogspot.com