Wednesday, April 9, 2008

Students took wave test.

Tuesday, April 8, 2008

Constanza redid the wavelength lab after school in which we measure the wavelength of laser light using a ruler. Students who previously did it got values that did not make sense, much too small a wavelength. When Constanza did it, she used a very small angle for the light hitting the ruler (> 4 degrees). The pattern showed clear maxima on the whiteboard but a lot of garbage in between. I think that with using a greater angle and having the maxima closer, it might be harder to distinguish the garbage from real maxima. Thinking that the garbage patterns were really maxima would give too many maxima for the same distance giving a wavelength that was too small. Constanza got a value of 700 nm which is pretty good.

Reviewed for the Waves test with a student led competition.

Students divided themselves into three teams and tried to answer questions posed by Jason, Brandon, and Travis.

Questions included refraction and critical angle, wave properties, a Doppler Effect problem with echoes (how many reflections to get above a certain frequency from a car moving towards a wall), which diffracts more: an audible sound wave or a radio wave.

Everyone did a great job!!

Monday, April 7, 2008

Showed Women in Art video clip - pretty cool.

Answered questions from WebAssign.

Travis led class in going over the refraction worksheet.

Went around room listing things that might be on Wednesday's test.

Jason and Travis will lead the review tomorrow.

Friday, April 4, 2008

Went over homework on superposition, critical angle (refraction), and Doppler Effect.

Started review using outline.

Assigned WebAssign: Chapter 18, Chapter 19, Problems in Waves.

Thursday, April 3, 2008

Collected diffraction labs. Checked measuring wavelength with a ruler data.

Went over homework problems on waves.

Students worked problems on standing waves and resonance and refraction.

For homework, assigned problems page 3: 1,2, page 5: 10, Page 8: 2,5, Page 9: 8

Waves test on Tuesday.

Wednesday, April 2, 2008

Reviewed diffraction lab.

Students derived 2-slit diffraction formula.

Beats: demo with QBASIC, demo with combs

Doppler Effect for Sound: Handed out and went over notes. Derived equations for moving receiver and moving source.

Handed out wave problem packet. Assigned problems from packet - due tomorrow.

Tuesday, April 1, 2008

Quick review of Reflection and Refraction.

Refraction demo of people walking.

Diffraction: Longer wavelengths diffract more. You can hear around a corner but not see around a corner.

Young's two slit diffraction.

Students did lab measuring wavelength using double slit and also using ruler.