March 13, 2007 Name ________________________________________
Visit these sites and rate them as to how well they presented each topic. 10 = best 1 = worst
____ 1. Electric Motor
http://www.walter-fendt.de/ph14e/electricmotor.htm
You should pause the simulation and verify that the force arrows are drawn in the correct direction. Resume the simulation. The black stripe through the middle of the red disk is an insulator. When the wires turn black there is no current in the wires. Note that the current in the loop of wire changes direction every half cycle as the contacts on the wires from the battery touch a different half circle.
Briefly describe the motion of the loop if the current did not reverse direction in the loop every half cycle.
____ 2. Water Molecule in a Microwave Field
http://www.colorado.edu/physics/2000/applets/h2o.html
The gray arrows represent the field of the microwave. The red circles are the hydrogen atoms. Water is a polar molecule, it has separation of charge.
True or False The arrows represent the electric field of the microwave, not the magnetic field.
Briefly explain why this applet shows how food gets hot in a microwave.
_____ 3. Polarizers
http://www.lon-capa.org/~mmp/kap24/polarizers/Polarizer.htm
A light source is located at the top center of the window. A detector is located at the bottom left. A text box with a % number shows the intensity of light reaching the detector. Start with one polarizer. You select the number of polarizers by clicking the radio button on the top left of the window.
a) Change the angle of the polarizer by dragging the scroll bar labeled Ang1.
What is the intensity of the light that reaches the detector? ________
b) Select two polarizers. What is the intensity when Ang1 is 0 and Ang2 is 90 (degrees)? ____________
____ 4. Electromagnetic Spectrum
http://lectureonline.cl.msu.edu/%7Emmp/applist/Spectrum/s.htm
Read and follow the directions at the bottom of the window. Explore various parts of the electromagnetic spectrum and learn how some EM waves are created and how they are detected. There are no questions for this applet.
____ 5. Doppler Effect (Uses Flash not Java, you may have to use a college computer for this site)
http://galileo.phys.virginia.edu/classes/109N/more_stuff/flashlets/doppler.htm
First, drag the slider on the right side of the screen down until the number in the box above the slider is zero. Then drag the microphone icon up so it is about an inch to the left of the red dot. The red dot will be a source of waves. Click on the play button at the bottom of the screen. You should hear clicks as a wave passes by the microphone. Drag the microphone to the right of the red dot. You should hear the same rate of clicks. Now drag the microphone about two more inches the right. Drag the slider up until the number in the box is about 0.4. Listen to the rate of the clicks while the source of the waves is approaching and then when the source of the waves is moving away from the microphone.
TRUE or FALSE The frequency of clicks is highest when the source of waves is approaching the microphone.
Next Week: Turn in this sheet and a one paragraph summary for a magazine or Internet article which is related to one of these topics: Maxwell’s Equations, Polaroids, Atomic Spectra, Balmer Series, Doppler Effect
Give the magazine reference (name, date, page) or the URL of the Internet site.