# Everyday Physics

## Terms

undefined, object
copy deck
Net force≠0 net torque=0
rod with forces applied at opposite ends in the same direction
Archimedes' principle
The magnitude of a buoyant force on a completely or partially submerged object always equals the weight of the fluid displaced by the object.
Planck's constant h
6.63 × 10-34 J s
Total momentum before collision
equals total momentum after collision
Electron and proton charge e
1.6 × 10-19 C
Period
time required to complete one cycle
azX
z+n
pressure at depth h
p + density x g h
11,000 kg/m^3
Boltzmann's constant k
1.38 × 10-23 J/K
Heat
mass x specific heat x temperature change
wavelength
length of a wave
static fluid formula
Fbottom=Ftop+mg where mg is the weight of the volume
Convert Fahrenheit to Celsius
5/9 [T(F)-32]
Engine efficiency cannot be 100%
you cant get as much out as you put in
Galileo
the first to do experimental studies of the laws of motion and was Imprisoned by Pope Urban VIII in 1633 for advocating the Copernican theory, also know as the heliocentric theory, that the earth was a planet revolving around the sun.
Net force
the total force (positive and negative) acting upon an object
Velocity required for an object to reach height h
initial velocity= the square root of 2gh
Heat capacity (specific heat)
the amount of heat that is required to raise the temperature of one g of a substance by 1 degree C.
mass flow rate formula
p x u x A
Present velocity
initial velocity = acceleration x time
c=3x10^8 m/s
?
continuity
v x A= constant
The US uses how much of the total world energy consumption?
25%
Newton's third law of motion
states that for every action there is an equal and opposite reaction.
Physics
The study of how objects behave (from the very tiny to the very big, and from the beginning of the Universe to its ultimate fate).
measure of density
kg/m^3
mechanical wave
a disturbance that propagates through a medium
restoring force
the force that brings a system back to equilibrium
density of air
1.25 kg/m^3
law of conservation of energy
the change in internal energy= the heat absorbed- the work done
Newton's first law of motion
also called the law on inertia, states that an object continues in its state of rest or of uniform motion unless compelled to change that state by an external force.
1 BTU
the heat needed to raise the temperature of 1 pound of water by 1 degree F
when ice in water melts what happens?
the level stays the same
Electron mass me
9.11 × 10-31 kg
order of states of matter stronger to lesser forces between atoms
solids, liquids, gases
Distance traveled
½ acceleration x time^2
wave
a disturbance that moves through something
period p of a mass m oscillating on a horizontal spring of force constant k
t=2π square root m/k frequency= square root k/m;/2π
volume fluid flow rate
gallons per minute (gpm), liters/s, cubic feet per minute (cfm) or m^3/s
Permeability constant µo
1.26 × 10-6 T m / A
Why does something move?
because nothing stops it
viscosity
a tendency for liquids to resist flowing.
density of aluminum
2,700 kg/m^3
bernoulli's equation
fluid flow velocity=u, fluid density=p (rho), fluid pressure=P P + ½ p x u^2 + p x g x h= constant
variation of pressure with depth
Fbottom-Ftop=mg=(density x vol) x g
First Law of thermodynamics
If energy is transferred and the internal energy of system B decreases by some amount then the internal energy of system A must incrase by the same amount.
Equilibrium
net force=0 net torque=0
period of a pendulum T of length L
2π x square root L/g
Projectile
an object that is thrown or struck or shot and then travels under the influence of gravity
Photon energy
hf
volume fluid flow rate formula
tube cross section area A, flow speed u vfr= u x A (m/s x m^2)
Centripedal acceleration=
Torque
force x lever arm
Stable structures
are wider at the base (which lowers their center of gravity)
T^4
Voltage
current x resistance
Brahe
Compiled the first detailed observational data on planetary motion (mars), without a telescope.
Acceleration
change in velocity / time
Kepler
analized brahe's data and verified the heliocentric theory. These regularities are known as Helpers Laws of Planetary motion.
Wave speed=
wavelength x frequency
Power (watts)
current x voltage energy/time (joules per second)
Pressure=
force per unit area
Heat
the energy that flows from one system to another because of their temperature difference.
Fluid force
pressure x area
density of water
1,000 kg/m^3
Flow through a pipe
π(P2-P1)D^4/128Ln n=fluid's viscosity
Buoyant force
weight of displaced water=volume of displaced water in liters x 10 n / liter
Resistance
voltage / current
Newton
wrote Principia in 1687. Made the 3 laws of mechanics and law of gravity. He also invented calculus.
the pressure of liquids _____ when it goes faster
decreases
Convert Celsius to Fahrenheit
9/5T(C)+32
velocity through a medium
c/n
ultrasound
sounds above 20,000 Hz
Stable
not easy to knock over
pressure depends on
number density x temperature
Newton's second law of motion
states that if a net force acts on an object, it will cause an acceleration of that object.
Internal energy
the sum of the energy of all the molecules in the system
Emissive
the efficiency with which an object emits thermal radiation. Is a number between 0 and 1. A good emitter has an e close to 1.
Time for an object thrown to reach maximum height
time= the square root of 2 x height / acceleration due to gravity
Acceleration due to gravity on the earth
-10 m/s^2
Speed of light c
3.0 ×108 m/s
incoming and outgoing flow rate formula
v1 x A1=v2 x A2
infrasound
sounds below 30 Hz
pressure does what when depth is increased
it increases
Center of gravity (CG)
the center of an object
Heat capacity equation
heat Q= mass of sample x specific heat x temp change
Pascal's principle
The pressure applied at one point in an enclosed fluid under equilibrium conditions is transmitted equally to all parts of the fluid.
Condition for stability
if the CG is above the edge, the object will not fall
Conservation of energy
you can't get more work out than the energy you put in
Conduction
heat is transferred directly through a material with no bulk movement of material
Quantum mechanics
new theory that explained behavior at the atomic level
Gas constant R
8.31 J / mole K
Velocity=
distance traveled / time
Newton's Second Law
f=mass x acceleration
Aristotle
believed that the natural state of objects was to be at rest
atmospheric pressure (atm)
100,000 n/m^2
Frequency
1 / period (time)
Engine efficiency
work done / heat in
Torque
the combination of force and point of application
Wavelength
c / f
Momentum
mass x velocity
entropy
the total disorder of an object
Rotational inertia (moment of inertia)
how much torque it takes to get an object rotating
definition of Bernoulii's equation
as the speed of a moving fluid increases, the pressure within the fluid decreases
Convert Celsius to Kelven
T(C) +273
Speed of light
18600 miles/sec
Second law of thermodynamics
if the temperature of system A is less then the temperature of system B then heat flows from B to A (hot to cold)
Change in internal energy
heat into system - work done by system
Mechanics
why things move
Gravitational constant G
6.67 × 10-11 Nm2/kg2
Net force=0 net torque≠0
rod with forces applied at opposite ends in opposite directions
Permittivity of free space o
8.85 × 10-12 C2 / Nm
The law of periods
The square of the period (T) of any planet is proportional to the cube of the semi-major axis (r) of its orbit, or T 2=(4π2/GM) r3, where M is the mass of the planet.
Weight
mass x gravity
Energy of motion (kinetic energy)
½ m v^2
The law of orbits
All planets move in elliptical orbits with the sun at one focus.
Thermal conductivity
the effectiveness of a material in conducting heat
the heat transfer by electromagnetic waves - thermal light waves
frequency of light
speed of light / wavelength
Convection
heat is carried from place to place by the bulk movement of either liquids or gasses
amplitude
maximum displacement from equilibrium