IGCSE Formula

Question 1

Average Speed** (s)** =

Answer 1

Total Distance (d)

 Total Time **(t)**

** **

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Question 2

Acceleration **(a) **=

Answer 2

change in velocity** (v-u) **

time taken (t)

Question 3

Hooke’s Law: Force F =

Answer 3

** k × x**

spring constant × extension

** **(Only up to the limit of proportionality)

Question 4

Resultant Force F =

Answer 4

m × a

mass × accleration

Question 5

Weight W =

Answer 5

m × g

mass × graviational field strength

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Question 6

g (on Earth) =

Answer 6

10m/s² or 10N/kg

Question 7

Density ρ =

Answer 7

mass (m)

volume (V)

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Question 8

Gravitatonal Potential Energy GPE =

Answer 8

m × g × h

mass × gravitational field strength × height change

Question 9

Kinetic Energy KE =

Answer 9

½ × m × v²

½ × mass × speed²

Question 10

Efficiency =

Answer 10

Useful Energy Output

Total Energy Input

Question 11

Work Done W =

Answer 11

= F × d

Force × distance moved in direction of force

or Energy Transferred

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Question 12

Power P =

Answer 12

Energy Transferred (E)

Time Taken (t)

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Remember Work Done = Energy Transferred

Question 13

Pressure (P) =

Answer 13

Force (F)

Area (A)

       ![An equation triangle showing pressure in liquids: F over P and A](http://www.bbc.co.uk/schools/gcsebitesize/science/images/triple_science/037_bitesize_gcse_tsphysics_work_pressureinliquids_304.gif "Pressure in liquids equation")

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Question 14

Boyles Law

Pressure × Volume =

P₁ × V₁ =

Answer 14

Consant

P₂ × V₂

Question 15

Heat energy supplied to change state E =

Answer 15

** l x m**

Specific Latent Heat x mass

Question 16

Heat energy supplied to raise the temperature E =

Answer 16

**m × c × Δθ **

or** m × c × (θ₂-θ₁)**

= mass × specific heat capacity × rise in temperature

Question 17

Current I** =**

Answer 17

Charge (Q)

Time (t)

Current is the rate of flow of charge

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Question 18

Potential Difference / Voltage V =

Answer 18

Energy E

Charge Q

Potential difference is the energy transferred per Coloumb of charge

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Question 19

Resistance R =

Answer 19

Voltage V

Current I

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Question 20

Electrical Power P =

Answer 20

I × V

Current × Voltage

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Question 21

Electrical Energy Transferred E =

Answer 21

P × t

Power × Time

or

** I × V × t**

Current × Voltage × time

Question 22

Transformers:

V_p =

V_{<strong>s </strong>}.

p.d across primary coil

p.d across secondary coil

Answer 22

N_p

N_s

number of turns in primary coil

number of turns in secondary coil

Question 23

Transformers

V_p × I_p=

Power In =

Answer 23

V_s × I_s

Power Out

(if 100% efficient)

Question 24

Resistors in series

R_Total =

Answer 24

R₁ + R₂ + …

Question 25

Resistors in Parallel

_ 1 _ =

R_Total

Answer 25

1 + 1 + …

R₁ R_{2 .}

Question 26

Frequency f =

Answer 26

_ 1 _

Period (time for 1 cycle)

** _ 1 _ **

T

Question 27

Wavespeed v =

Answer 27

f × λ

frequency × Wavelength

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Question 28

Frequency =

Answer 28

Number of waves

TimeTaken