Showing posts with label Notes. Show all posts

Formulae

Here are the formulae from Physics, chemistry and Biology. These are very important for entry test preparation also for FSc exams.

Physics


v = u + at
v² = u² + 2as
s = ut + ½at²

F = ma

F = Gm1m2/r2

a = v2/r

Static friction = FN mS

Dynamic friction = FN mD

MA = load/effort = number of supporting ropes in a frictionless pulley system

VR = distance moved by effort / distance moved by load = number of supporting ropes

Efficiency = work out / work in

Moment = F x perpendicular distance to pivot point

Momentum = mv

Smv before collision = Smv after collision

Impulse = Ft

PE = mgh

KE = ½mv2

Work done = Fd

Power = Fd/t

Dl = kF

Y = stress / strain = (F/A) / (Dl/l)

S = stress / strain = (perpendicular F/A) / (Dx/l)

B = stress / strain = DP / (DV/V)

f µ Ö (k/m)

T = 2p Ö (l/g)

r = m/V

Upward force on a body = weight of fluid displaced by that body

Hydrostatic pressure = rgh

r1A1v1 = r2A2v2

P1 + rgh1 + ½rv12 = P2 + rgh2 + ½rv22

Velocity of sound in a fluid, v = Ö (B/r)

v µ Ö (T/mw)

Velocity of sound in a solid = Ö (Y/r)

Velocity of a wave in a taut string = Ö (tension/[mass/length])

dB = 10log10(I/10-12)

Beat frequency = difference between the two frequencies

f' = f(C±Vd / C±Vs)

F = kq1q2/r²

E = F/q

Between two parallel plates, E = V/d
Concerning a point charge, E = kq/r²

V = Fd/q

V = IR

For resistors in series, RT = R1 + R2 + R3 + ...

For resistors in parallel, 1/RT = 1/R1 + 1/R2 + 1/R3 + ...

Resistivity = RA/l

C = q/V = permitivity x A/d

For capacitors in series, 1/CT = 1/C1 + 1/C2 + 1/C3 + ...

For capacitors in parallel, CT = C1 + C2 + C3 + ...

P = IV

If a.c., P = (Imax/Ö2) (Vmax/Ö2) = Imax Vmax/2

n1sin i = n2sin r

1/f = 1/u + 1/v

Lens power = 1/f where f is the focal length in m. Lens power is measured in diopters.

Two lenses in contact: 1/F = 1/f1 + 1/f2

E = hf

At = Aoe-kt

t½ = ln2/k

Chemistry


Number of moles = mass in grams / molecular weight

PV = nRT

KE µ T

v µ Ö(T/mw)

PT = P1 + P2 + P3 + ...

P = mole fraction of solvent x Po

DP = mole fraction of solute x Po

DTBP = kb (molality of solute particles)

DTFP = -kf (molality of solute particles)

Osmotic Pressure = RT [molarity of solute particles]

pH = -log10[H+]

pOH = -log10[OH-]

Kw = [H+] [OH-] = 10-14 (at 25oC)

Ka = [H+] [A-] / [HA]

pKa = -log10Ka

Kb = [HA] [OH-] / [A-]

pKb = -log10Kb

Ka Kb = 10-14

pKa + pKb = pKw = 14

pH = pKa + log10[A-]/[HA]

DE = q - w

DG = DH - TDS

DG = DG° + RTlnQ

Keq = eDG°/-RT

Reaction Order
dA/dt
Integrated Forms
0
dA/dt = k
At = A0 - kt
1
dA/dt = kA
At = A0e-kt
2
dA/dt = kA2
1/At = (1/A0) + kt

E = E° - (RT/nF)lnQ = E° - (0.026/n)lnQ

Keq = enFE°/RT

DG° = -nFE°

Biology



p2 + 2pq + q2 = 1