These
are all of the equations you need to know for Physics examinations...
at each stage it is assumed you remember the ones from the previous
stage... so its worth transferring them properly to your mental 'hard
drive'!
Remember
to take care when you write the equation letters... they are symbols
NOT part of your handwriting!
Special care with I
for current it shouldn't be possible to confuse it with l
for
length or 1 (the number one)!
Equation
in words
Symbolic
representation
Year
Key
Stage
speed
=distance travelled
time taken
v
= d/t
Y7
KS3
acceleration =
change in velocity
time
a
= v/t
Y8
KS3
density
= mass
volume
= m/V
Y7
KS3
force
= mass x acceleration
F
= ma
Y9
KS3
work
done = force x distance moved in the direction of that force
W
= Fs
Y9
KS3
momentum
= mass x velocity
p
= mv
Y12
AS
power
= energy transferred
time
taken
P
= E/t
Y8
KS3
power
= work done
time taken
P
= W/t
Y9
KS3
weight
= mass x gravitational field
strength
w
= mg
Y7
KS3
kinetic
energy = half x mass x (velocity squared)
EK=
1/2mv2
Y12
KS4
change
in gravitational potential energy = mass x gravitational field
strenth x difference in height
DGPE
= mgh
Y9
KS3
pressure
= force applied
contact area
P
= F
A
Y7
KS3
Gas
Law: pressure x volume of a gas = number of moles x molar
gas constant x absolute temperature
pV
= nRT
Y12
AS
Gas
Law: combination of Boyle's Law and Charles' Law
P1V1
= P2V2
T1
T2
NB
Temperature MUST be in Kelvin
Y11
KS4
charge
= current x time
DQ
= It
Y10
KS4
Ohm's
Law: Potential difference = current x resistance
V
= I R
Y8
KS3
Ohm's
Law applied to the full circuit: Electromotive force = current
x (sum of the circuit resistance and the internal resistance of
the cell)
EMF
= I (R
+ r)
Y12
AS
power
= current x potential difference
P
= I V
Y8
KS3
energy
transferred in a component = charge passing through it x potential
difference acorss it
W
= QV
Y10
KS4
resistance
= resistivity x length
cross sectional area
R
= l
A
Y12
AS
wavespeed
= frequency x wavelength
v
= f
for electromagnetic
radiation v = c giving:
c = f
Y8
KS3
centripetal
force = mass x speed2
radius of path
FC
= mv2
r
Y13
A2
Electrical
energy changed into heat = potential difference x current x time
E
= VI t
Y9
KS3
Inverse
square law for force on a mass in a gravitational field of
another mass: Force is proportional to the product of the masses
and inversely proportional to the square of the distance between
them
FG
= - G m1 m2
r2
NB the
minus sign indicates it is ALWAYS attractive
Y13
A2
Inverse
square law for force on a charge in an electric field of another
charge: Force is proportional to the product of the charges and
inversely proportional to the square of the distance between them
FE=
1 Q1 Q2
40
r2
NB the
overall sign indicating wherther it is attractive (negative)
or repulsive (positive) comes from the signs of the charges.
Also, although the constant
of proportionality is complex it is a similar relationship to
above.
Y13
A2
capacitance
= charge stored
potential difference
C =
Q
V
Y13
A2
ratio
of the voltages across the coils of a transformer = the ratio
of the turns on the coils
V1
= N1
V2
N2 NB the 1 could be P
for primary and the 2 could be s for secondary - it doesn't matter
which is which!
Y11
KS4
LOJ November 2000/revised
October 2001/revised November 2002
v/t
= m/V
0
r2
