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PHYSICS FORMULA SHEET
Topic 1: Motion, forces and energy
1.1 Physical quantities and measurement techniques:
 density= mass/ volume
1.2 Motion
 Speed = Distance/ Time
 Average speed= Total distance travelled / Total time taken
 Acceleration= Change in velocity/ Change in time
1.3 Mass and weight
 Weight= Mass x Gravitational field strength
1.4 Density
 Density = Mass/ Volume
1.5 Forces
1.5.1 Effects of forces
 F= k(x); F= Force, k = Spring constant and x =Extension
 F = ma: F =Net force; m= mass and a = acceleration
1.5.2 Turning effect of forces
 Moment of a force = Force × Perpendicular distance from the pivot
1.6 Momentum
 Impulse = Force x Time
 Resultant force = Change in momentum / Change in time
1.7 Energy, work and power
1.7.1 Energy
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Kinetic energy= 0.5 m v2; m= mass and v= velocity
Potential energy = mgh ; m= mass, g= gravitational field strength and h= height of the
object above the ground
1.7.2 Work
 Work = Force x Distance travelled in the direction of the force
1.7.3 Energy resources
 Percentage efficiency = [ Useful energy output / Total energy input] x 100
 Percentage efficiency = [ Useful power output / Total power input] x 100
1.7.4 Power
 Power= Work done / Time taken
 Power= Energy transferred / Time taken
1.8 Pressure
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Pressure = Force / Area
Pressure = Height x Density x gravitational field strength
2 Thermal physics
2.1.3 Gases and the absolute scale of temperature
 Temperature in Kelvin = Temperature in Celsius + 273
 Boyle's law PV= Constant
2.2 Thermal properties and temperature
2.2.2 Specific heat capacity

Specific heat capacity = Change in energy / Mass x Change in temperature
3 Waves
3.1 General properties of waves
Wave Equation:
velocity = frequency x wavelength
3.2 Light

Refractive Index (n)= Sin(i)/Sin(r) [ Use this when measures f angle "i" and angle "r" are
known]
 Refractive Index (n) = 1/Sin(c) [ use this when the value of critical angle is known]
3.2.4 Dispersion of light
 No formulae
3.3 Electromagnetic spectrum
 Know the value of speed of light: 3.0 × 108m/s
3.4 Sound
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Know the value of Human Audio Frequency: 20 Hz to 20 000 Hz
Know the value of speed of sound in air: 330–350 m/s
4 Electricity and magnetism
4.2.2 Electric current
 I=Q/t [ Current = Charge per unit time]
4.2.3 Electromotive force and potential difference
 E=W/Q [ E= Emf]
4.2.4 Resistance
 R=V/I
4.2.5 Electrical energy and electrical power
 P = IV
4.3.2 Series and parallel circuits
4.3.3 Action and use of circuit components
Equation for two resistors used as a potential divider R1 / R2 = V1 / V2
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4.5.6 The transformer
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Transformer Equation: Vp / Vs = Np / Ns
Efficiency equation: Ip Vp= Is Vs
P= I2R