# Everyday Physics

## Terms

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- 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
- density of lead
- 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=
- velocity squared / radius
- Torque
- force x lever arm
- Stable structures
- are wider at the base (which lowers their center of gravity)
- Thermal radiation
- 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
- Radiation
- 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
- Avagadro's number N
- 6.02 × 1023
- Thermodynamics
- the study of heat and its transformation into mechanical energy
- measurement of pressure
- Pascal (Pa) or pounds per square inch (psi)
- The law of areas
- A line joining a planet and the sun sweeps out equal areas in equal time.
- Einstein
- shows in 1905 that newtons laws were not valid for objects moving with speeds near the speed of light.