Overview of Physics

physics

physics

the study of how and why things move

classical mechanics

the branch of physics dedicated to understanding how large objects move at moderate speeds

projectile motion

motion in 2-dimensions under constant acceleration due to gravity

force

push or pull

weight

force of gravity at or near the earth's surface

work

the application of force along a displacement

energy

the ability to do work

harmonic motion

movement back and forth about a point of equilibrium (creates waves)

wave

translation of energy rather than a transfer of particles

Galileo

developed the kinematic equations which explain projectile motion

Newton

developed the laws of motion

James Prescott Joule

proved conservation of energy

Hooke

Worked with springs

thermodynamics

the branch of physics dedicated to understanding energy transformations and the eventual degradation of all forms of energy into heat

Heat

total random kinetic energy of all the particles in an object; infrared

heat transfer

conduction, convection or radiation

conduction

heat transfer by contact

conductor

a material in which heat moves through easily

insulator

a material in which heat does not move easily

convection

heat transfer by motion of material (ex weather)

radiation

heat transfer in the form of light

phases of matter

qualitative measure of heat

solid

low heat, definite shape and volume particles move back and forth at a point of equilibrium (harmonic motion)

crystalline

solids with an organized structure

amorphous

solids with a disorganized structure

liquid

medium heat, no definite shape, definite volume, particles run over one and other

viscosity

measure of a liquids resistance to flow

gas

high heat, no definite shape or volume, particles are free to move

Boyles law

when pressure goes up, volume goes down

Charles law

when temperature goes up, volume goes up

plasma

highest heat, no definite shape or volume ionized gas

evaporation

vaporization on a liquid's surface

boiling

vaporization inside a liquid

solid to gas

sublimination

gas to solid

deposition

gas to plasma

ionization

plasma to gas

recombination

temperature

average measure of heat

conservation of energy

energy is neither created or destroyed, it just changes form, heat moved from an area that is hot to an area that is cold, you can never reach absolute zero in a finite number of steps

efficiency

a measure of the loss of energy to heat

2nd law restated

you can never be 100% efficient

2nd law restated

entropy is always increasing in a closed system, theoretically the best it can do is stay the same. It will never decrease. Max entropy-> max equilibrium-> max probability-> max chaos

entropy

a measure of unusable heat

Death of the universe according to thermodynamics

there are stars in the universe. Stars are concentrated heat, and thus there is order in the universe. However, in a long time all the stars will burn out and their heat will be evenly distributed. The universe will be at roughly 10K and in a state of maximum entropy and max chaos

William Thompson

discovered absolute zero (lord Kelvin)

Carnot

developed theoretical engines that looked at efficiency and supported the third law of thermodynamics

Optics

branch of physics dedicated to understanding the properties light

reflection

when light comes to a change in a material and bounces off

refraction

bending of light from on material to another

diffraction

the spreading of light behind the opening of a barrier

Snell

developed an equation for refraction

Huygen

his principle is used to explain diffraction, said any point on wavefront can be treated as source

electro-magnetism

branch of physics dedicated to understanding the nature and movement of objects with a charge and objects with polarity

static charge

charge that doesn't move

charge

property of an object that describes how it interacts electrically

polarity

property of an object that describes how it interacts magnetically

electric force

force of attraction or repulsion between two objects of charge at some distance

current

flow of charge at a given time

potential

potential energy per unit charge

Alessandro Volta

made the first battery

Micheal Faraday

saw a relationship between electricity and magnetism and explained it with drawings called field lines

James Clark Maxwell

unified electricity and magnetism using mathematics

Special relativity

the study of (fast moving) objects in inertial reference frames

frame of reference

a zero point from which physically quantities are measured

inertial reference frame

a reference frame that moves at a constant velocity

2 postulates of special relativity

1. the laws of physics are invariant in all inertial frames

2. the speed of light in a vacuum is constant in all inertial frames regardless of the speed of the source or the observer

Lorentz

developed transformation equations that allow for time dilation (time slows down as you go faster) and length contraction (lengths get smaller as you go faster)

Poincare

you can't measure velocity in an absolute sense and his math shows a speed limit for matter to be the speed of light in a vacuum. The math makes mass increase with velocity

Einstein

developed special relativity

General relativity

the study if objects in non-inertial (accelerating) frames

Equivalence property

you can't tell the difference between gravity and an equivalent force

Curved Space

massive objects curve space and gravity is inertial response to curved space

Black hole

a massive object will curve space so much that light can't escape.

worm hole

tunnel between space and time

time travel

a worm hole with one end going at relativistic speeds would allow it.

Einstein

developed general relativity

Schwartzchild

derived an equation that calculates the event horizon (radius) of black holes

General relativistic death of the universe

-enough mass will cause the universe to gravitational collapse in on itself in a Big Crunch. (Big bang -> Big Crunch) *current bright matter isn't enough *so we search for dark matter *recently the situation has become more complicated, because we've observed the universe accelerating away from itself due to dark energy

quantum mechanics

physics on a very small scale. It was developed to explain the interaction between light and matter. It is a place where waves become particles (light), and particles become wave (matter)

2 reasons why light can be considered a particle

1.) UV catastrophe: light emitted from heated objects doesn't peak in the UV. explained by quantizing light 2.) photoelectric effect: when light hits certain materials, it creates a current

Heisenberg's uncertainty principle

the act of measuring something will alter that which you measure

Bohr

said that electrons had orbits called energy levels and transitions between these orbits are the spectral lines of an element

Debroglie

made the first equation that explains matter as a wave

Schrodinger

made a wave equation that explains all matter as wave. (His equation is to matter as a wave Newtons laws of motion are to matter as a particle)

Planck

explained the UV catastrophe

Einstein

explained the photoelectric effect

Heisenberg

explained the uncertainty principle

P.A.M Dirac

developed relativistic quantum mechanics which predicts the existence of antimatter. (The positron which is the antimatter of the electron was discovered in 1932)

Scientific method

1.) define a problem (You will have a test.) 2.)gather info (covering what material, type) 3.)form a hypothesis (easy and short study time) 4.)test hypothesis (take the test) 5.)gather data and analyze (get your grade) 6.)draw conclusions (the study time was inadequate) 7.) test again (take another test)

Metric system

base 10 international standard unit of measurement.

precision

property of a device that determines its ability to measure. Can also be expressed as the consistency of a measurement

accuracy

the correctness of a measurement

ruler

measure length (precision- .5mm (standard shapes, volume) (length: distance/displacement))

graduated cylinder

measures volume (Volume: space an object takes up)

triple beam balance

measures mass Precision- .05g (mass: amount of matter in an object, a measure if inertia) (Inertia: an object resistance to changes in motion)

spring scale

measures force

Density

physical quantity that depends on an object's mass and volume D=m/v

Frame of reference

a zero point from which physical quantities are measured

Position

an object’s location

displacement

a change in position in a certain direction