Due Date for PDR #4

What do you think of moving the due date for PDR #4 to Monday so you have another weekend to finish it?

Missing Tuning Fork

A tuning fork mysteriously vanished during sixth hour today. If you know of its whereabouts please inform Mr Washenberger.

OUT TODAY

Sorry Folks, I am out sick today, Tuesday, 2/26/2008. The sub has a copy of the worksheet for you and you can find it on my schedule page.
See you Wednesday, I hope.

Myth Busters

Check out the Myth Busters Rube Goldberg. They do a great description of how the project works.

ECLIPSE

It's 9:00 PM Wednesday, February 20. Go outside NOW and see the eclipse.

Test on Thursday

Be sure to prepare by completeing the study guide. You know where to find a copy.

Is it working?

I am having trouble with the animation to do the Two Point Lab at home. Anyone else having similar trouble?

Absent?

For those of you who may be absent today, check the schedule and refer to the wave notes. On the two point practice find all of the points of destructive interference. draw in the node lines and then use one of the equations to find the wave length.

Snells Law Sheet

Answers to Snell's Law Sheet:

1) 1.375, 2) 3.4 m/s, 3) 0.51 m/s, 4) 28 degrees, 5) 1.4, 4.07 m/s, 6) 15 degrees,
7) 4.9 cm/s, 3.75 cm/s 8) 17.3 degrees

Huygen's Principle

Check out the animations that show Huygens principle. They help you to understand how waves reflect and refract.

Traveling Wave refraction

Point sources and Huygen's Principle

Crest and Trough

If the crest is the top of the wave, the trough can be thought of as "the anticrest"!

Wave Sheet

Here are the answers to the wave sheet:
1) .62 m 2) 44 m/s 3) 5.2 Hz 4) 8.4 Hz, 27.7 cm/s 5) 1.65 cm .... 6) 0.5 m
7) (Yup) 8) 185 Hz 9) 1.45 m 10) 2.27 cm 11) 23.6 cm/s

remember the equations: v=f(lambda) and L = n/2(lambda)

mew or mu?

An experimental physicist performs an experiment involving two cats, and an inclined tin roof.
The two cats are very nearly identical; same sex, age, weight, breed, eye and hair color.

The physicist places both cats on the roof at the same height and lets them both go at the same time. One of the cats fall off the roof first so obviously there is some difference between the two cats.

What is the difference?

One cat has a greater mew.

Stroboscope!!!

The waves in the ripple tanks as I mentioned earlier can be studied by looking through a stroboscope (pictured at the left). The stroboscope allows the observer to "Freeze" the wave so that it can be more accurately studied.

Cold Out!

Researchers in Fairbanks Alaska announced today that they have discovered a superconductor which will operate at room temperature.

- 45 F is very cold!!!!!!

Ripple Tanks and Wave Properties

The classes are using the ripple tanks this week and next. These are great for observing a variety of wave properties. This week we see wave reflections from a variety of boundaries. Additonally, we will study wavelength, frequency and velocity of waves.

We have fifteen of these ripple tank setups so students have a great opportunity to participate in the activities.

Next week we'll see Snell's Law and two point source interference. To see an animation of what the ripple tanks more or less look like click on the link http://www.falstad.com/ripple/ and put the setting 1 plane source, 1 freq. in the second box.

Is anyone seeing this?

Hey, I am wondering if anyone is actually looking at any of this. If so, could you give me some feedback about that and if you have any suggestions?

I do have the notes from the last couple of days posted on the web. If you want to save writing in the next couple of days you could print out the notes and just bring them along to class. Then have them out as I go through and add any detail you might think is necessary. You can find the notes at: schedule
I have found that it works best in internet explorer.