F
A
W = Fx cos
θ
E
k
=
1
2
mv2
E
p
= mgh
efficiency =
useful energy output
total energy input
× 100%
F = kx
E =
1
2
Fx
E =
1
2
kx2
stress =
F
A
strain =
x
L
Young modulus =
stress
strain
Unit 2 – Electrons, Waves and Photons
ΔQ = IΔt
I = Anev
W = VQ
V = IR
R =
ρL
A
P = VI P = I
2
R P =
V
2
R
W = VIt
e.m.f. = V + Ir
V
out
=
R
2
R
1
+ R
2
× V
in
v = fλ
λ
=
ax
D
d sin
θ = nλ
E = hf E =
hc
λ
hf = φ + KE
max
λ =
h
mv
R = R
1
+ R
2
+ …
1
R
=
1
R
1
+
1
R
2
+ …
– G M
r
2
T
2
= (
4p
2
GM)
r
3
f =
1
T
ω =
2p
T
= 2pf
a = –(2pf)
2
x
x = A cos(2pft)
v
max
= (2pf) A
E = mc
Δθ
pV = NkT
pV = nRT
E =
3
2
kT
Unit 5 – Fields, Particles and Frontiers of
Physics
E =
F
Q
F =
Qq
4p
ε
0
r
2
E =
Q
4p
ε
0
r
2
E =
V
d
F = BIL sin
θ
F = BQv
φ = BA cosθ
induced e.m.f. = – rate of change of magnetic
flux linkage
V
s
V
p
=
n
s
n
p
Q = VC
W =
1
2
QV W =
1
2
CV 2
time constant = CR
x = x
0
e
–
t
CR
C = C
1
+ C
2
+ …
1
C
=
1
C
1
+
1
C
2
+ …
A =
λN
A = A
0
e
–λt
N = N
0
e
–λt
λt
½
= 0.693
ΔE = Δmc
2
I = I
0
e
–μx