Collected Saving Jack Labs.
Only 10 of 18 students present.
Students solved wave and standing wave problems.
Summarized properties of waves: reflection, refraction (Snell's Law, index of refraction, critical angle)
Started diffraction - Young's Two Slit example. The closer the slits, the farther apart the maxima.
Monday, March 31, 2008
Friday, March 21, 2008
Friday, March 21, 2008
Lab Day for Waves
Demonstrated Belly-Dancing Tuning Forks.
Set up Dave Cross Wave Machine. Students were asked to determine how the wave speed depends on the number of nodes and the tension in the string.
Set up resonance tube with water. Students were asked to calculate the resonant depths and then verify by experiment.
Snell's Law Lab. Students were asked to measure the index of refraction of water and calculate the speed of light in water.
Reviewed results for the last 20 minutes of class.
Demonstrated Belly-Dancing Tuning Forks.
Set up Dave Cross Wave Machine. Students were asked to determine how the wave speed depends on the number of nodes and the tension in the string.
Set up resonance tube with water. Students were asked to calculate the resonant depths and then verify by experiment.
Snell's Law Lab. Students were asked to measure the index of refraction of water and calculate the speed of light in water.
Reviewed results for the last 20 minutes of class.
Thursday, March 20, 2008
Thursday, March 20, 2008
Gave students 30 minutes to finish up their "Save Jack" Labs.
Handed back RA 18.1, RA 18.2
Went over work sheets
Showed examples of superposition. Propagate waves than just algebraically add up the waveforms.
Electromagnetic spectrum: Radio waves, microwaves, infrared, Visible (R-O-Y-G-B-I-V), Ultraviolet, X-rays, gamma rays. Used v = wavelength * freq to calculate the wavelengths of AM and FM radio waves. Wavelength of microwave from microwave oven.
Used Wien's Law to calculate wavelength emitted by our bodies (infrared). Red wavelengths ~700 nm. Violet ~ 400 nm.
Demo that TV emits radio waves that we can pick up on radio set to static AM.
Discussed how microwaves cook food - resonant frequency with water molecules.
Showed how remotes, which emit IR, can be detected using a photocell and speaker, or by cell phone camera.
Standing waves: String fixed at both ends. v = sqrt(tension/(mass/length)).
Drew patterns of fundamental (first harmonic), and second and third harmonics for string, open pipe, and pipe open at one end and closed at the other. Derived general formulas for frequency for the various harmonics.
Used water filled pipe to find resonances.
Handed out worksheets on superposition and standing waves.
Handed back RA 18.1, RA 18.2
Went over work sheets
Showed examples of superposition. Propagate waves than just algebraically add up the waveforms.
Electromagnetic spectrum: Radio waves, microwaves, infrared, Visible (R-O-Y-G-B-I-V), Ultraviolet, X-rays, gamma rays. Used v = wavelength * freq to calculate the wavelengths of AM and FM radio waves. Wavelength of microwave from microwave oven.
Used Wien's Law to calculate wavelength emitted by our bodies (infrared). Red wavelengths ~700 nm. Violet ~ 400 nm.
Demo that TV emits radio waves that we can pick up on radio set to static AM.
Discussed how microwaves cook food - resonant frequency with water molecules.
Showed how remotes, which emit IR, can be detected using a photocell and speaker, or by cell phone camera.
Standing waves: String fixed at both ends. v = sqrt(tension/(mass/length)).
Drew patterns of fundamental (first harmonic), and second and third harmonics for string, open pipe, and pipe open at one end and closed at the other. Derived general formulas for frequency for the various harmonics.
Used water filled pipe to find resonances.
Handed out worksheets on superposition and standing waves.
Wednesday, March 19, 2008
Tuesday, March 18, 2008
Tuesday, March 18, 2008
Lab Day
Students did the:
Speed of Sound in Air Lab
Tones, Vowels, and Telephones Lab (didn't finish)
Speed of Sound in Aluminum Lab
Asked for write-ups that were terse and pithy covering the main idea and results.
Tomorrow we do the "Save Jack" lab
Students did the:
Speed of Sound in Air Lab
Tones, Vowels, and Telephones Lab (didn't finish)
Speed of Sound in Aluminum Lab
Asked for write-ups that were terse and pithy covering the main idea and results.
Tomorrow we do the "Save Jack" lab
Monday, March 17, 2008
Monday, March 17, 2008
Went over Thermodynamics test.
Intro lecture on waves. A wave is a wiggle in space and time.
A wave is a way of transferring energy without the movement of matter from one place to another.
Waves can be classified as transverse or longitudinal, or mechanical or electromagnetic. Went over properties of each.
Derived wave speed formula.
Students did the Slinky Lab
Homework: Plan for Save Jack Lab on Wed.
Intro lecture on waves. A wave is a wiggle in space and time.
A wave is a way of transferring energy without the movement of matter from one place to another.
Waves can be classified as transverse or longitudinal, or mechanical or electromagnetic. Went over properties of each.
Derived wave speed formula.
Students did the Slinky Lab
Homework: Plan for Save Jack Lab on Wed.
Thursday, March 13, 2008
Wednesday, March 12, 2008
Went over RA 17.2.
Lectured on the Second Law of Thermodynamics.
Explained the various statements of the Second Law.
Defined entropy. Showed how to calculate the change in entropy.
Gave students a practice test on Thermodynamics which they worked on in groups.
Handed out RA 18.1 and RA 18.2 for homework over the long weekend.
Lectured on the Second Law of Thermodynamics.
Explained the various statements of the Second Law.
Defined entropy. Showed how to calculate the change in entropy.
Gave students a practice test on Thermodynamics which they worked on in groups.
Handed out RA 18.1 and RA 18.2 for homework over the long weekend.
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