MCAT-physics

kilo

10^3 (k)

Mega

10^6 (M)

Giga

10^9 (G)

Tera

10^12 (T)

hecto

10^2(h)

deca

10^1 (da)

Deci

10^-1 (d)

centi

10^-2 (c)

milli

10^-3 (m)

Micro

10^-6 (μ)

nano

10^-9 (n)

Pico

10^-12 (p)

30-60-90 triangle

45 45 90 triangle

sin/cos values to remember

horizonal projectile motion=

cos

vf and vi formula with a and change in x

vf^2=vi^2+2achange in x

newton's laws:

1. objects at rest/motion will stay at rest/motion

2. F=ma

3. equal and opposite forces

4 fundamental forces

1. gravity

2. electromagnetic force

(dont need to know these)

3. strong nuclear force

4. weak nuclear force

center of mass

(x1m1+x2m2+x3m3)/(m1+m2+m3)

Fstatic (the maximum it can be, but if less than max then it is opp of force applied to move the object)

(coefficient of friction)(normal force)

for gravity questions g=

m1m2/(r^2)

centripetal acceleration

v^2/r

Hooke's law: force needed to compress/stretch a string by x is

F=kx

torque

F(d)sin()

angle between force and lever arm

work=

F(d)cos()

angle between force and horizontal

unit=joules=1 N(m)= (kgxm^2)/s^2

mechanical advantage of ramps vs pulley

less force, same work

mechanical advantage= length of incline/height of incline

power

work/time

units: W=1 J/s

kg⋅m2⋅s−3

for projectile motion trig

angle formed with the x axis

vx=vcos()

vy=vsin()

velocity

area under a velocity v time graph is displacement

acceleration

area under an acceleration v velocity graph is change in velocity

kinematics equation missing acceleration

d=(vavg)t or d=((change in v)/2)t

kinematics equation missing displacement

vf=vi+at or (change in v)=at

kinematics equation missing final velocity

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

kinematics equation missing time

vf^2=vi^2+2a(change in x)

motion on an inclined plane

g perpendicular= gcos()

g parallel=gsin()

Kinetic Energy (KE)

1/2mv^2

energy is proportional to

mass

energy and ____ are two ways of talking about the same thing

work

gravitational potential energy

mass x gravity x height

or

mgh

potential energy of a spring

1/2kx^2

when choosing between using kinematics or conservation of energy, remember that

time is not used in energy calculations

work

kinetic energy final-kinetic energy initial

pressure

force/area

units: 1 Pa or 1 N/m^2

work

pressure (change in volume)

think of the scenario in which a piston is moving in and out of a cylinder, changing the volume

if a gas doing work to expand a balloon

then the gas has to cool because it is using energy

Fahrenheit =

2(degrees Celsius) + 32

first law of thermodynamics

0. Two bodies in thermal equilibrium are at the same T

1.Energy cannot be created or destroyed

2. The total entropy of a system must increase in every spontaneous reaction

3. The entropy of a pure, perfectly crystalline compound at absolute zero (0 K) is zero.

Change U=Q-W

first law of thermodynamics

-the total energy change of a system is equal to the transfer of energy into the system via heat minus the work performed BY the system on its surroundings

isolated system-

no exchange of energy or matter

closed system-

no exchange of matter, only exchange of energy

open system

exchange of matter and energy

system gaining energy (heat and work)

heat into system, work by system

system losing energy

heat out of system, work on system

second law of thermodynamics

two ways of saying:

1. if two objects are in thermal contact but not in thermal equilibrium, then heat energy will flow from object with higher temp to object of lower temp

2. the entropy of an isolated system will increase over time

heat

a mechanism of energy transfer and has unites of energy

temperature

static property proportional to kinetic energy

change in volume and change in length are proportional to change in temperature

change in length= (coefficient of thermal expansion constant specific to the substance)(length)(change in temperature)

PV=

NRT

zeroth law of thermodynamics

if one system (A) is in thermal equilibrium with two other systems (B and C), then systems B and C must also be in thermal equilibrium with eachother

lowest kelvin temp possible is

0 degrees (or absolute zero)

isochoric

volume remains constant

isobaric

constant pressure

isothermal

constant temp

adiabatic

process where no heat exchange takes place

density =

mass/volume

remember mass and _____ are not the same

weight

molarity

moles/liters

density of water (need to memorize)

1000 kg/m^3 or 1 kg/L or 1 g/mL or 1 g/cm^3

specific gravity

how dense something is compared to water (bc it is a proportion it does not have units)

pressure=

force/area

pressure on an object submerged in fluid=

(density of object)(g)(depth of submersion)

absolute pressure

hydrostatic prerssure of submerged object + pressure of atmosphere

the percentage of an object that will be submerged in water is proportional to its

specific gravity

buoyant force is equal to

the weight of the fluid displaced by the object

Pascal's Principle

The rule that when force is applied to a confined fluid, the increase in pressure is transmitted equally to all parts of the fluid.

watch video

higher velocity of a fluid

the more likely it is to become turbulent

the flow rate and the pressure drop are proportional to each other

aka a large pressure drop will cause flow rate to increase

poiseulle's law equation (describes flow of incompressible fluids through a cylinder)

know how variables relate to eachother, so if change one what the effect will be, memorize formula

Bernoulli's Law

Law stating that pressure in a moving fluid is less when the fluid is moving faster.

general ruled of ideal fluids:

narrower tube->higher velocity

narrower tube->lower pressure

higher velocity->lower pressure

venturi effect

narrower tube-> lower pressure (venturi effect), higher velocity

higher velocity->lower pressure

laminar flow

a smooth pattern of flow

(opposite of turbulent)

relationship between fluid velocity and cross-sectional area of the pipe through which the fluid is travelling

v1A1=v2A2

so fluid velocity and cross-sectional area are inversely proportional

properties of ideal fluids

1. the fluid is incompressible

2. the fluid is not viscose

3. the fluid exhibits laminar flow

increased flow speed resulting from being forced through a confined space results in

a zone of low pressure

scalar quantities do not have

a direction

(but vector quantities do have direction)

E (magnitude of electric field)=

(kq)/r^2 or F/q

The SI units of the electric field are newtons per coulomb (N/C), or volts per meter (V/m)

Work (in an electric field)

W=(kQq)/r

potential energy of a chrarge

(kQq)/r

-same as work

V, electric potential

(kQ)/r

Conductivity

A material's ability to allow heat to flow

(sigma)(area/length)

-sigma is a constant that is the inverse of p

Resistivity

A material's opposition to the flow of electric current.

p(length/area)

-p is a constant

dimagnetic

no unpaired electrons

paramagnetic

Atom or substance containing unpaired electrons and is consequently attracted by a magnetic field

magnetic fields cannot be blocked

but, it can be rerouted with a material that conducts better than the materials around it, ie copper

electric field lines are drawn

from positive to neg charges

an insulator does not have free electrons, but when a charged object is brought near it...

polarization does occur at an atomic level

electric potential energy=

electric potential (charge)

electric potential=

k(Q/r)

1atm

= 101kPa = 760 mmHg