MCAT Equations

buoyant force

p = density

V = volume

g = gravity

Density

mass/volume

Absolute pressure

Atmospheric pressure + gauge pressure

Volume of Submerged Object

object density/fluid density = Vsubmerged/Vobject

specific gravity

Flow rate

(Cross-sectional Area)(Velocity)

Continuity equation

A1V1=A2V2

Velocity

distance/time

VAT

Vi+at

VAX

Vf^2 = Vo^2 + 2ax

TAX

x = (vi x t) + 1/2at^2

Spring Force

k = spring constant

x = distance spring travels

Spring Potential Energy

Energy stored in a stretched or compressed spring. Measured in Joules.

Us=½kx²

Work

force x distance (cosθ)

Force of gravity

mg

kinetic force of friction

F parallel (friction)

mg sin theta

F perpendicular (friction)

mg cos theta

Torque

force x distance (sinθ)

Torque conservation

T one side = T other side

Snell's law

n1sinθ1 = n2sinθ2

Doppler equation

Doppler effect

An observed change in the frequency of a wave when the source or observer is moving

Photon energy

E = hf = hc/wavelength

Formula for light

c = λv

thin lens equation

1/f = 1/di + 1/do

Lens power

P = 1/f where f is in meters

Magnification equation

magnification = - image size/actual size

Electric field

voltage/distance

in N/C or V/m

Effective voltage (Vrms)

another term for RMS (root mean square) voltage

Electrical force

the effect of the membrane potential on the ion's movement

charge x electric field

Capacitance

electrostatic constant x area/distance between plates

Capacitor storage

C = QV

Capacitor in series

Resistor in parallel

Capacitor in parallel

Voltage in parallel

Vt = V1 = V2

Current in parallel

It = I1 + I2

Voltage in series

Vt = V1 + V2

Current in series

It = I1 = I2

Resistor in series

Current (I)

the flow of electrical charge between two points

Potential Energy of Capacitor

Volts

joules per coulomb

Equation for magnetic force on a charged particle when it moves through a magnetic field

F = qVb sin θ

charge x velocity x magnetic field x sin θ

Latent heat

the energy absorbed or released during a change in state

latent heat = energy absorbed or released x mass

Specific heat

the heat required to raise the temperature of the unit mass of a given substance by a given amount (usually one degree).

photoelectric effect

max KE of electron = planck's x frequency - work function

Molarity

Molar mass

grams/mole

Delta G

G = change in free energy

R = gas constant (8.31)

T = temp in kelvin

ln Keq = natural log of dissociation rate

Delta G cell

n = moles of electrons

F = faraday constant

Ecell = cell potential

Kcat

The catalytic rate constant of an enzyme

Vmax/enzyme concentration

Michaelis-Menten equation

reaction velocity

Vmax = max velocity

S = moles of substrate

Vo = initial velocity

Km = sub concentration at 1/2 Vmax

catalytic efficiency

Kcat/Km

Kcat = ability to catalyze reaction

Km = ability to bind to substrate

Rf

distance moved by substance/distance moved by solvent

nonpolar = faster movement up

Cardiac output

The volume of blood ejected from the left side of the heart in one minute.

Henry's law

the solubility of a gas in a liquid is directly proportional to the partial pressure of that gas on the surface of the liquid

Ideal gas law

PV=nRT

Henderson-Hasselbalch equation

pH = pKa + log [base]/[acid]

Keq

[products]/[reactants]

Q < Keq

forward direction

- Δ G

Q > Keq

reverse direction

+ Δ G

Kw (autoionization of water)

Ka x Kb

pH

-log[H+]

Osmotic pressure

iMRT

Arrhenius equation

shows the relationship between the rate constant and temperature