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Formulae

These will not be given to you

Velocity
v = x
      t
v = velocity - m/s
x = displacement  - m
t = time – s
Average speed
Av speed = distance
                       time

Acceleration
a = change in velocity
                 time
a = (v – u)
            t
a = acceleration – m/s2
 v = final velocity – m/s
u = final velocity – m/s
t – s
Force
F = ma
F = Force – N
m = mass – kg
a = accln m/s2
Momentum
P = m x v
P = momentum - kgm/2
m = mass –kg
v = velocity – m/s
Density
ρ = m
       V
ρ = density – kg/m3
m = mass – kg
V = volume m3
Work
W = Fx
W = work – J
F = Force – N
x = distance – m
Kinetic energy
KE = ½ mv2
KE – J
m = mass – kg
v = velocity – m/s
Gravitational
Potential
Energy
GPE = mgh
GPE – J
m = mass – kg
g = gravitational field
strength – N/kg
h = vertical height – m
Weight
w = mg
W = weight – N
m = mass – kg
g = gravitational field
strength – N/kg
Pressure
P = F
      A
P = pressure – Pa
F = Force N
A = Area – m2
Pressure in fluids
P = hρg
P = pressure – Pa
ρ = density – kg/m3
h = vertical height – m
Moment
Moment = Force x distance
Moment – Nm
Electric Charge
Q = It
Q = charge – C
I = current – A
t = time – s
Ohm’s Law
V = IR
V = voltage – V
I = current – A
R = resistance Ω
Electrical Power
P = IV
P = power – W
I = current – A
V = voltage – V
Electrical Energy
E = IVt
E = energy J
I = current – A
V = voltage – V
t = time – s
transformer
Vp  = Np
Vs      Ns

Input power = output power
VpIp = VSIS
100% efficiency
Vp = voltage in primary
Vs = voltage in secondary
Np = number of turns in primary
Ns = number of turns in secondary
I = current
Wave equation
v = fλ
v = velocity m/s
f = frequency – Hz
λ = wavelength – m
Refractive index
n = sin i
      sin r
i = angle of incidence
r = angle of refraction
Critical angle
Sin c = 1
             n






Copied from the front of an examination papers







tso there is no excuse for not knowing the units of acceleration!