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Formula
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Word
Formula
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Unit
|
|
v = d/t
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speed = distance/(time taken)
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m s-1
|
|
W = Fd
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Work done = Force x distance moved in
the direction of the force
|
J
|
|
P = W/t
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Power = energy transformed/(time
taken)
|
W or Js-1
|
|
E = Pt
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Electrical energy = Power x
time
Electrical energy in kWh = Power in kW x time in hours
|
J or kWh
|
|
|
moment of a force about a pivot =
force x perpendicular distance from force to pivot
|
Nm
|
|
|
sum of clockwise moments = sum of
anticlockwise moments
|
Nm
|
|
a = Dv/t
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acceleration = change in
velocity/change in time
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ms-2
|
|
F = ma
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Force = mass x acceleration (constant
mass)
|
N
|
|
v = f x l
|
wave speed = frequency x wavelength
|
ms-1
|
|
Q = It
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Charge = current x time (constant
current)
|
C
|
|
V = IR
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potential difference = current x
resistance
|
V
|
|
P = IV
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electric power = current x potential
difference
|
W or Js-1
|
|
W = mg
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weight = mass x gravitational field
strength
|
N
|
|
K.e = ½ mv2
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kinetic energy = ½ mass x velocity2
|
J
|
|
g.p.e = mgh
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Gravitational potential
energy = mass x g x height
|
J
|
|
V = W/Q
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potential difference = energy
transformed/charge transferred
|
V
|
|
R = V/I
|
Resistance of element = potential
difference across component / current
|
ohms
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