Lectures on Physics has been derived from Benjamin Crowell's Light and Matter series of free introductory textbooks on physics. See the editorial for more information....

Index E...

earthThe wobbly earth
 The earth and moon get a divorce
earthquakeMechanical work done in an earthquake
 Collapse of the Nimitz Freeway in an earthquake
eclipseGravity bending light
EinsteinMass Into Energy
 Albert Einstein
electric fieldSuperposition of electric fields
 Summary - Fields
 The Electric Field
 Voltage related to electric field
 Discussion Questions - Electric Fields
electrical circuitSummary - Electricity
electrical energyPotential Energy
electrical forceThe Quest for the Atomic Force
electricitySummary - Electricity
electromagnetic wavesElectromagnetic Waves
electronThe Electron
 Summary - Atom
electron spinElectron Spin
electron-positron annihilationElectron-positron annihilation
elephantThe wavelength of an elephant
elevatorAn Elevator
elongation of springsObjects Under Strain
emission of electronsEmission of electrons in a cathode ray tube
 Kinetic Energy
 Force, Energy, and Power
 Summary - Energy
 Simplifying the Energy Zoo
 All Energy is Potential or Kinetic
 The concept of work
 Efficiency and grades of energy
 Energy and Relative Motion
 How new forms of energy are discovered
 Energy stored in a battery
 Energy stored in a capacitor
energy conceptSummary - Energy Concept
energy conversionConverting one form of energy to another
energy equivalentA rusting nail
energy in fieldsCalculating Energy in Fields
energy levelEnergies of States in Hydrogen
energy of a vibrationSummary - Energy in Vibrations
 Entropy increases in heat conduction
 A book sliding to a stop
 Using a refrigerator to decrease entropy?
 Entropy and evolution
Ernest RutherfordThe Planetary Model of the Atom
etherThe Principle of Relativity
evolutionEntropy and evolution
exampleEnergy released by a comet impact
 Converting kilowatt-hours to joules
 Human wattage
 Conservation of mass
 Converting one form of energy to another
 Heating a swimming pool
 Irish coffee
 You take the high road and I’ll take the low road
 Dropping a rock
 Gravitational PE converted directly into heat
 Mechanical work done in an earthquake
 Pushing a broom
 A violin
 Energy production in the sun
 A toy gun
 Gravitational potential energy
 An ice skater pushing off from a wall
 Absorbing an impact without recoiling?
 Dragging a refrigerator at constant velocity
 Accelerating a cart
 A Cannon
 Ion Drive for Propelling a Spacecraft
 The Tail of a Comet
 A Spinning Top
 Momentum and kinetic energy in firing a rifle
 The wobbly earth
 The earth and moon get a divorce
 Momentum and kinetic energy of a glacier
 Q of a stereo speaker
 Getting rear-ended
 Pool balls colliding head-on
 A collision of pool balls viewed in the c.m. frame
 The slingshot effect
 Walking into a lamppost
 Ion drive for spacecraft
 A toppling box
 An explosion
 The bola
 A two-car crash with sticking
 Shooting pool
 A Turbine
 A figure skater pulls her arms in
 Changing the axis
 Earth’s slowing rotation and the receding moon
 Colliding asteroids described with different axes
 A system with its center of mass at rest
 Angular momentum of a rigid object
 How torque depends on the direction of the force
 Gravitational torque on an outstretched arm
 A flagpole
 An application of calculus
 Pressure in U.S. units
 Atmospheric pressure in U.S. and metric units
 Getting killed by a pool pump
 Pressure of lava underneath a volcano
 Atmospheric pressure
 Which temperature scale to use
 Volume related to temperature
 Pressure in a car tire
 Earth’s senescence
 A piston, a refrigerator, and a space suit
 Entropy is additive
 Entropy isn’t changed by a Carnot engine
 Entropy increases in heat conduction
 Entropy is increased by a non-Carnot engine
 A book sliding to a stop
 Using a refrigerator to decrease entropy?
 Maxwell’s daemon
 Entropy and evolution
 The heat death of the universe
 Hawking radiation
 A carnival game
 Period and frequency of a fly’s wing-beats
 Frequency of a radio station
 The pendulum
 The moons of Jupiter.
 Water in a U-tube
 The range of energies of sound waves
 Exponential decay in a trumpet
 Ions moving across a cell membrane
 An opera singer breaking a wineglass
 Collapse of the Nimitz Freeway in an earthquake
 Collapse of the Tacoma Narrows Bridge
 Emission and absorption of light waves by atoms
 Piano strings ringing in sympathy with a sung note
 Changing the pitch of a wind instrument
 Decay of a saxophone tone
 Q of a radio receiver
 Q of a stereo speaker
 Nuclear magnetic resonance
 Hull speed
 Wavelength of radio waves
 Doppler-shifted sound from a race car
 Doppler shift of the light emitted by a race car
 Fish have internal ears
 Whale songs traveling long distances
 Long-distance radio communication
 Radio transmission
 A magnetic compass
 A television tube
 Flow of electrical charge in wires
 Flow of electrical charge across cell membranes
 Emission of electrons in a cathode ray tube
 Decay of Pb-212
 A reaction occurring in the sun
 Number of photons emitted by a lightbulb per second
 Number of electrons flowing through a lightbulb
 Energy stored in a battery
 Units of volt-amps
 Power dissipated by a battery and bulb
 Resistance of a lightbulb
 Two lamps on the same household circuit
 Three resistors in parallel
 An arbitrary number of identical resistors in parallel
 Dependence of resistance on cross-sectional area
 Incorrect readings from a voltmeter
 Getting killed by your ammeter
 Dependence of resistance on length
 More than two equal resistances in series
 Two lightbulbs in series
 Choice of high voltage for power lines
 A charged balloon
 ATLAS accelerator
 Gravitational field of the earth
 Reduction in gravity on Io due to Jupiter’s gravity
 Superposition of electric fields
 Dipole moment of a molecule of NaCl gas
 Field generated by an electric eel
 Relating the units of electric field and voltage
 Voltage associated with a point charge
 Field of a uniformly charged rod
 Hallucinations during an MRI scan
 The generator
 The transformer
 Getting killed by a solenoid
 Energy stored in a capacitor
 Potential energy of a pair of opposite charges
 Energy in an electromagnetic wave
 An alternative optical test
 A Searchlight
 A flat mirror
 An anti-shoplifting mirror
 A shortcut for real images
 Snell's Law
 Ocean waves near and far from shore
 Double-slit diffraction of blue and red light
 The correspondence principle
 Spacing of the fringes at small angles
 Gravity bending light
 Black holes
 A rusting nail
 Electron-positron annihilation
 KE compared to mass equivalent at low speeds
 The correspondence principle for mass-energy
 Looking for tall basketball players
 C Dating
 Radioactive contamination at Chernobyl
 The hot potato
 Probability distribution for radioactive decay
 Average lifetime
 Sample Example
 Momentum of a photon
 A microwave oven
 What is the proportionality constant?
 The wavelength of an elephant
 The typical wavelength of an electron
 Spectra of thin gases
 The stability of atoms
 Chemical bonds in hydrogen molecules
 An estimate for electrons in atoms
 A book lying on a table
 Pushing a box up a hill
 A barge
 A pulley
 An Elevator
 Terminal velocity for falling objects
 A passenger riding the subway
 Forces on a sailboat
 A car crash
 An accelerating bus
 Weight and mass
 Calculating terminal velocity
 Finding final speed, given time
 Extracting acceleration from a graph
 Converting g to different units
 Numerical calculation of a negative acceleration
 Acceleration with a change in direction of motion
 A skydiver
 Saving an old lady
 The units of G
 Newton’s third law
 Pluto and Charon
 Force required to turn on a bike
 Don’t hug the center line on a curve!
 Acceleration related to radius and period of rotation
 A clothes dryer
 More about clothes dryers!
 Slow down before a turn, not during it
 Velocity vectors in relative motion
 The galloping horse
 A component of a force vector
 Pushing a block up a ramp
 The second derivative of a vector
 The integral of a vector
 A fire-extinguisher stunt on ice
 Order of addition
 Finding the magnitude and angle from the components
 Finding the components from the magnitude and angle
 Negative components
 Adding components
 LA to Vegas, graphically
 A car going over a cliff
 Forces in perpendicular directions on the same object
 The center of mass as an average
 Velocity in the x-t graph
 Scaling of the area of a triangle
 Scaling of the volume of a sphere
 Scaling of a more complex shape
 Cost of transporting tomatoes
 Rain falling into a moving cart
exerciseExercise: Torque
 Exercise: Vibration
 Exercise: Worksheet on Resonance
 Object and Image Distances
 How strong are your glasses?
exercisesHomework Problems - Conservation of Energy
 Homework Problems
 Homework Problems
 Homework Problems
 Homework Problems
 Homework Problems
 Homework problems
 Homework problems
 Homework problems
 Homework problems
 Homework problems
 Homework problems
 Homework Problems 2
 Homework Problems 1
 Homework problems
 Homework problems
expansion of universeEvidence for Repulsive Gravity
experimentThe Scientific Method
explosionAn explosion
exponential notationScientific Notation
eyeEyes and Sight
 Refraction and the Eye
 Discussion - Refraction and Images
eyeglassesHow strong are your glasses?

Last Update: 2011-03-23