PHYS1001 Physics 1 (Regular) Formula Sheet
Physics 1 (Regular) Formula Sheet
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CC1529 Semester
PHYS1001 Physics 1 (Regular) Formula Sheet
Vectors
~A = Axˆi+ Ay jˆ+ Azkˆ
A =
∣∣∣~A∣∣∣ = √A2x + A2y + A2z
~R = ~A+ ~B = ~B+ ~A
Rx = Ax +Bx, Ry = Ay +By, Rz = Az +Bz
~A · ~B = AB cosφ =
∣∣∣~A∣∣∣ ∣∣∣~B∣∣∣ cosφ
~A · ~B = AxBx + AyBy + AzBz
~C = ~A× ~B, C = AB sinφ
Cx = AyBz − AzBy, Cy = AzBx − AxBz,
Cz = AxBy − AyBx
Simple motions
Constant acceleration in one direction:
v = v0 + at
x = x0 + v0t+
1
2
at2
v2 = v20 + 2a(x− x0)
x− x0 =
(
v0 + v
2
)
t
Projectile motion:
x = (v0 cosα0)t
y = (v0 sinα0)t− 1
2
gt2
vx = v0 cosα0
vy = v0 sinα0 − gt
Uniform circular motion:
arad =
v2
R
= ω2R =
4pi2R
T 2
Kinematics
~r = xˆi+ yˆj+ zkˆ
~vav =
~r2 −~r1
t2 − t1 =
∆~r
∆t
~v = lim
∆t→0
∆~r
∆t
=
d~r
dt
vx =
dx
dt
, vy =
dy
dt
, vz =
dz
dt
~aav =
~v2 − ~v1
t2 − t1 =
∆~v
∆t
~a = lim
∆t→0
∆~v
∆t
=
d~v
dt
ax =
dvx
dt
, ay =
dvy
dt
, az =
dvz
dt
Force and Momentum∑
~F = m~a, ~FA on B = −~FB on A
w = mg
fk = µkn, fs 6 µsn
d~P
dt
=
∑
~Fext
~p = m~v, ~J = ~p2 − ~p1 =
t2∫
t1
∑
~F dt
∑
~F =
d~p
dt
,
∑
~Fext = M~acm, M =
∑
i
mi
~P = m1~v1 +m2~v2 +m3~v3 + . . . = M~vcm
~rcm =
∑
i
mi~ri
M
=
m1~r1 +m2~r2 +m3~r3 + . . .
m1 +m2 +m3 + . . .
CC1529 Semester 1, 2018 Page 2 of 3
Work and Energy
K =
1
2
mv2, Ugrav = mgy, Uel =
1
2
kx2
F = −kx
Wtot = K2 −K1 = ∆K
W = ~F ·~s = Fs cosφ
W =
∫ P2
P1
F cosφ dl =
∫ P2
P1
~F · d~l
Pav =
∆W
∆t
P =
dW
dt
= ~F · ~v
Wel = −∆Uel, Wgrav = −∆Ugrav
E = K + U
∆E = Wother
Periodic Motion
ω = 2pif =
2pi
T
, f =
ω
2pi
=
1
T
ω =
√
k
m
, ω =
√
κ
I
ω =
√
g
L
, ω =
√
mgd
I
Fx = −kx
x = A cos(ωt+ φ)
E =
1
2
mv2x +
1
2
kx2 =
1
2
kA2 = constant
x = Ae−(b/2m)t cosω′t, ω′ =
√
k
m
− b
2
4m2
bcritical = 2
√
km
A =
Fmax√
(k −mω2d)2 + b2ω2d
Rotational Motion
ωz =
dθ
dt
, v = rωz
αz =
dωz
dt
=
d2θ
dt2
arad =
v2
r
= ω2r, atan =
dv
dt
= r
dω
dt
= rα
IP = Icm +Md
2, vcm = Rω
I = m1r
2
1 +m2r
2
2 + . . . =
∑
i
mir
2
i
τ = rF sin θ, ~τ = ~r× ~F∑
τz = Iαz,
∑
~τ =
d~L
dt
K =
1
2
Mv2cm +
1
2
Icmω
2
z , P = τzωz
W =
∫ θ2
θ1
τz dθ, Wtot =
1
2
Iω22 −
1
2
Iω21
~L = ~r× ~p = ~r×m~v (particle)
~L = I~ω (rigid body)
Moments of inertia
Thin rod, axis through centre: I =
1
12
ML2
Thin rod, axis through one end: I =
1
3
ML2
Rectangular plate, axis through centre:
I =
1
12
M(a2 + b2)
Thin rectangular plate, axis along edge: I =
1
3
Ma2
Hollow cylinder: I =
1
2
M(R21 +R
2
2)
Solid cylinder: I =
1
2
MR2
Thin-walled hollow cylinder: I = MR2
Solid sphere: I =
2
5
MR2
Thin-walled hollow sphere: I =
2
3
MR2
CC1529 Semester 1, 2018 Page 3 of 3
Thermal physics
∆L = αL0∆T, ∆V = βV0∆T
Q = mc∆T, Q = nC∆T, Q = ±mL
pV = nRT = NkT N = nNA
CV =
3
2
R (ideal monatomic gas)
CV =
5
2
R (ideal diatomic gas)
CV = 3R (ideal monatomic solid)
CP = CV +R, γ =
CP
CV
vrms =
√
3RT
M
mtot = nM = nNAm
e =
W
QH
= 1 +
QC
QH
= 1−
∣∣∣∣QCQH
∣∣∣∣
eCarnot = 1− TC
TH
=
TH − TC
TH
KCarnot =
TC
TH − TC
eOtto = 1− 1
rγ−1
Ktr =
3
2
nRT,
1
2
m(v2)av =
3
2
kT
Mechanical waves
v = λf, k =
2pi
λ
ω = 2pif = vk, v =
√
F
µ
y(x, t) = A cos(kx± ωt)
y(x, t) = (ASW sin kx) sinωt (standing wave)
String fixed at both ends:
fn = n
v
2L
= nf1 (n = 1, 2, 3, . . .)
f1 =
1
2L
√
F
µ
β = (10 dB) log
I
I0
W =
∫ V2
V1
p dV, ∆U = Q−W
dU = dQ− dW (infinitesimal process)
K =
|QC |
|W | =
|QC |
|QH | − |QC |
∆S =
∫ 2
1
dQ
T
(reversible process), S = k lnw
H =
dQ
dt
= kA
TH − TC
L
, Hnet = Aeσ(T
4 − T 4s )
W = nCV (T1 − T2)
=
CV
R
(p1V1 − p2V2) (adiabatic process, ideal gas)
=
1
γ − 1(p1V1 − p2V2)
W = nRT ln
(
V2
V1
)
Reversible Processes for Ideal Gases:
Adiabatic (no heat transfer):
Q = 0, pV γ = constant
Isochoric (constant volume): W = 0
Isobaric (constant pressure): W = p(V2 − V1)
Isothermal (constant temperature)
Longitudinal sound waves
v =
√
B
ρ
(fluid), v =
√
Y
ρ
(solid rod)
v =
√
γRT
M
(ideal gas)
fn =
nv
2L
(n = 1, 2, 3, . . .) (open pipe)
fn =
nv
4L
(n = 1, 3, 5, . . .) (stopped pipe)
fL =
v + vL
v + vS
fs, sinα =
v
vS
fbeat = |fa − fb|