Physics 125 - General Physics II
Online resources
Here is a short list of useful links to some learning resources for this course. Note: some of the simulations use Java plugins for a web browser. Unfortunately, in the last few years, this feature has been eliminated from the Firefox and Chrome browsers. So these simulations will only work with a properly-configured Internet Explorer browser. These are indicated by (IE only).
We will be getting into some material in Ch. 20 that requires a knowledge of waves, you may want to browse through some of these simulations: they show animation of various concepts from waves and sound. In addition, you should study Chapters 13 and 14 in the text to be sure you know the basics of waves (especially if you are a transfer student who did not take Physics 124 here at WIU).
Reflection of waves on a string, with fixed or free boundaries.
Superposition of waves for several cases.
Fourier synthesizer with sound. (requires Java-enabled browser)
For more simulations that I used last semester, see the Physics 124 resources web page.
Some examples of scalar and vector fields (to motivate electric field in Ch. 15):
Temperature - a scalar field indicated by colors - notice also that the boundaries between colored regions are constant temperature contours
Streamlines of wind - this is one way to represent a vector field - the wind would carry a balloon along a streamline in the direction of the wind velocity
Wind plot - an example of a vector field indicated by flags, motivated by the use of flags placed up in the wind to indicate which way it is blowing
Physlets for electrostatics (for Ch. 15 and 16):
Third-law force pair between charges - Coulomb's Law (IE only)
Distance dependence of Coulomb's Law (IE only)
Electric field and field lines with movable test charge (IE only)
A test charge in a uniform field (and "not a test charge") (IE only)
Analogy with gravity (point charges) (IE only)
Electric Field of a point charge (IE only)
Electric Field of a dipole (IE only)
Electric Field of two like charges (IE only)
Motion of a test charge (not necessarily along the field lines!) (IE only)
Physlets for DC circuits:
Conventional vs. actual current (IE only)
RC circuits (IE only)
Physlets for magnetism:
Earth's magnetic field (IE only)
Electric charge in a magnetic field (IE only)
Helical motion (IE only)
Physlets for electromagnetic waves:
Moving charge, user controlled
Electric fields due to a moving point charge (IE only)
Slow-motion simulation of an electromagnetic wave
Physlets for Ch. 22 and 23: Geometrical Optics:
Animated gif: illustration of traveling pulse and reflection at boundaries
Reflection and refraction of waves (by Huygen's principle, which we haven't covered, but I'll do this in class)
Reflection and refraction of rays (by Snell's Law)
Image formation by a converging lens (should run in all current browsers)
Virtual Optical Bench - requires some practice (IE only)
The Human Eye - simulates the normal and near- or farsighted eye, and how a corrective lens helps to form an image on the retina (IE only)
Physlets for Ch. 24: Physical Optics
Interference of two circular waves (needed to understand double-slit diffraction)
Double-slit diffraction (uses alpha instead of theta, k instead of n)
Single-slit diffraction (uses alpha instead of theta, k instead of n)
Ripple tank simulation (you can add a second source to see interference)
Ripple tank simulation (add your own sources and move them around) (IE only)
Thin Film - showing transmitted and reflected wave (IE only)
Thin film interference with white light - simulates soap film colors, but there is quite a bit of extra detail in the text (link unavailable).
To discuss polarization by absorption, recall that EM waves are transverse, as seen in the slow-motion simulation, and the polarization direction is along the E vector. This polarization can be along one axis, say the x axis if the wave travels along z, or along a perpendicular direction like the y axis, or along some other arbitrary direction (but still transverse) as shown in this simulation of several states of polarization (link unavailable). After seeing these simulations, it should be easier to understand the demonstration that used three linear polarizers (over the overhead projector) to illustrate Malus' Law.
We also want to understand polarization by reflection. Review the interaction of the wavefronts with the surface during reflection by looking at the simulation of Huygen's principle and its application to reflection. Then recall that radiation of a dipole is suppressed in the direction of the dipole, as seen when you choose the SHO option from the drop-down menu in the Retarded fields physlet. Now review the material in your text, on pp. 800-802, especially Fig. 24-23.
Physlets for Ch. 27 and 28: Atomic Structure and Quantum Mechanics
A Blackbody Spectrum simulation shows how the color changes as an object is heated to very high temperatures. (link unavailable)
Recall that strings confined to a length can vibrate as standing waves. A membrane like a drum head can also vibrate as a standing wave. These vibrations have particular frequencies and shapes, and are somewhat analogous to the standing wave of the electron (wavefunction) as it is confined around a nucleus by the electric force of the nucleus. The electron wavefunctions around a nucleus are called orbitals, and are shown in just about every chemistry book. Web sites are available to explore atomic orbitals. There is a site that let you rotate a d-orbital to help visualize it. Similar orbitals are responsible for bonding in molecules, like the hydrogen molecule. In some structured materials and semiconductor devices, the electron wavefunctions look more like the standing waves of a rectangular membrane.
Ch. 29: Nuclear Structure
I have prepared some PowerPoint presentations which have links to web sites with nuclear data, etc. If the links do not work from within the PowerPoint presentation, use these links:
Part 1: Biographical sketch of Becquerel
Part 2: X-ray Form Factors, Attenuation Lengths, etc.
Part 3: Korean database with nuclear levels for Co-60 Lund database of nuclear isotope data indexed through a periodic table
Part 4: Berkeley Table of Isotopes Brookhaven NUDAT charts Nuclear wallet cards
IAEA Nuclear Safety homepage nuclide chart with Java controls (France, may be tricky to use)
Simulation of radioactive decay chains
Some more resources for radiation safety:
CDC radiation emergencies – isotopes, see: http://www.bt.cdc.gov/radiation/
CDC radiation emergencies http://www.bt.cdc.gov/radiation/index.asp
EPA radiation information http://www.epa.gov/radiation/
EPA link to fact sheets about commonly encountered radionuclides http://www.epa.gov/radiation/radionuclides/index.html