Formulae for the MCAT

Note: This list may not be exhaustive. Examinees should understand these formulae. Not all of them need to be memorized though. Judgement should be used in deciding which to memorize.

PDF file: Formulae for the MCAT

Physics

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

F = ma

F = Gm₁m₂/r²

a = v²/r

Static friction = F_N m_S

Dynamic friction =F_N m_D

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/I₀)

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, R_T = R₁ + R₂ + R₃ + ...

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

Resistivity = RA/l

C = q/V = permitivity x A/d

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

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

P = IV

If a.c., P = (I_max/Ö2) (V_max/Ö2) = I_max V_max/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

A_t = A_oe^-kt

t½ = ln2/k

General Chemistry

Number of moles = mass in grams / molecular weight

PV = nRT

KE µ T

v µ Ö(T/mw)

P_T = P₁ + P₂ + P₃ + ...

P = mole fraction of solvent x Po

DP = mole fraction of solute x Po

DT_BP= k_b (molality of solute particles)

DT_FP = -k_f (molality of solute particles)

Osmotic Pressure = RT [molarity of solute particles]

pH = -log₁₀[H⁺]

pOH = -log₁₀[OH^-]

K_w = [H⁺] [OH^-] = 10^-14 (at 25^oC)

K_a = [H⁺] [A^-] / [HA]

pK_a = -log₁₀K_a

K_b = [HA] [OH^-] / [A^-]

pK_b = -log₁₀K_b

K_a K_b = 10^-14

pK_a + pK_b = pK_w = 14

pH = pK_a + log₁₀[A^-]/[HA]

DE = q - w

DG = DH - TDS

DG = DG° + RTlnQ

K_eq = e^DG°/-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

K_eq = e^nFE°/RT

DG° = -nFE°

Biology

p² + 2pq + q² = 1