EXTRA - Key Equations For Physics IGCSE

Here I will be grouping together all the key equations for Physics IGCSE

Topic 1 - Forces and Motion

average speed = distance travelled/ time taken                             v = s/t

acceleration = change in velocity/ time taken                                a = (v-u)/t

force = mass x acceleration                                                           F = ma

weight = mass x gravitational field strength                                  w = mg

momentum = mass x velocity                                                        p = mv

moment = force x perpendicular distance from pivot                   moment = F x d

sum of anticlockwise moment = sum of clockwise moment

Topic 2 - Electricity

power = current x voltage                                                              p = I x V

energy = power x time                                                                   E = p x t

energy = current x voltage x time                                                  E = I x V x t

charge = current x time                                                                  Q = I x t

voltage = current x resistance                                                        V = I x R

Topic 3 - Waves

wave speed = frequency x wavelength                                          v = f x λ

law of reflection: angle of incidence = angle of reflection

law of refraction: refractive index,                                                  n = sin i/sin r                     (sin i = sin angle of incidence, sin r = angle of refraction)

total internal reflection: refractive index,                                        n = 1/sin c

Topic 4 - Energy

efficiency = useful energy output from system/ total energy output into system x 100

work = force x distance                                                                   w = F x d    

GPE = mass x gravitational field strenght x height                         GPE = m x g x h

KE = ½ mass x speed²                                                                    KE = ½mv²

power = work done/ time taken                                                       P = W/t     

Topic 5 - Solids, Liquid and Gases

density = mass/ volume                                                                   p = m/v

pressure = force/ are                                                                        p  = F/A

pressure difference = height x density x gravity                              p = h x p x g  (in liquids)

pressure is proportional to absolute temperature                           P1/T1 = P2/T2

Topic 6 - Magnetism

input voltage/ output voltage = primary turns/ secondary turns     Vp/Vs = n1/n2

none in Topic 7 - Radioactivity

 

Units for Forces and Motion

The units that you need to know for the topic forces and motion are as followed (SI units are just the basic unit of each measurement)

Kilogram (kg)

This is the SI unit of mass. One kilogram = 1000 grams (1kg = 1000g)

Metre (m)

This is the SI unit of distance and displacement.

(Displacement is dependent on direction as well as size, for example if someone went 50m north and then 20m south, the total distance travelled would be 70m, but displacement would be 30m.)

Metre/Second (m/s)

This is the SI unit of speed or velocity

Metre/Second (m/s²)

This is the SI unit of acceleration

Newton (N)

This is the SI unit of force.

Second (s)

This is the SI unit of time.

Newton/Kilogram (N/Kg)

This is an unit of acceleration

We know this from the equation F = ma (Force = Mass x Acceleration) 

Rearranged this reads, Acceleration = Force/ Mass

N + Kg are the units of force and mass respectively, so acceleration = N/Kg

Kilogram Metre/Second (kg m/s)

This is the SI unit of momentum

We know this from the equation momentum = mass x velocity

kg + m/s are the units of mass and velocity respectively, so momentum = kg m/s

These will all be explained in depth in the next few posts. 

I will answer any questions in the comments below.

The Syllabus

In this 'blog' you will find notes compiled from many resources that will be sure to get you an A* in GCSE Physics

In this post I'm going to give you an overview of the syllabus, each sub sequential post will give notes on one sub topic.

Forces and Motion

 

Units

Movement and Position

Forces, Movement, Shape and Momentum

Astronomy

 

Electricity

 

Units

Mains Electricity

Energy and Potential Difference In Circuits

Electrical Charge

 

Waves

 

Units

Properties of Waves

The Electromagnetic Spectrum

Light and Sound

 

Energy Resources and Energy Transfer

 

Units

Energy Transfer

Work and Power

Energy Resources and Electrical Generation

 

Solids, Liquids and Gases

 

Units

Density and Pressure

Change of State

Ideal Gas Molecules

 

Magnetism and Electromagnetism

 

Units

Magnetism

Electromagnetism

Electromagnetic Induction

 

Radioactivity and Particles

 

Units

Radioactivity

Particles