26 February 2010

How far is Avogadro's number in meters? (6.023 x 10^23 m)

Avogadro's number...How big is it?
Can a person count to this number in their lifetime (counting once per second)?

How far away from the Earth would you be if you traveled this number of
meters? See this video on youtube for an excellent, 9 minute description!
http://www.youtube.com/watch?v=A2cmlhfdxuY  Listen carefully to the video, and fill out this worksheet on google docs and answer the following questions: http://docs.google.com/Doc?docid=0ARNbGsVH1evCZGQ5MjluM2dfNzBkMzMydDNmdA&hl=en

24 February 2010

Adding similar sine waves causes "BEATS"

What happens when you add similar sine waves together? Any musician can tell you: as you tune an instrument closer and closer to the correct tone, you start to hear "beats", when the tone sounds louder and softer and louder and softer and ... You get the idea.

What does it look like? Take a look.
 Ok, ok. I get it. What's the homework? Your job is to reproduce this sound, and draw it, using the following link: http://www.falstad.com/fourier/e-logsound.html
 and write a summary of what Beats are using the following article: http://en.wikipedia.org/wiki/Beat_%28acoustics%29

14 February 2010

Blood tests are so complicated?

When you go to get a blood test, for what is the doctor looking? That depends on your age, gender, and symptoms. See the following website for all the details: http://en.wikipedia.org/wiki/Reference_ranges_for_common_blood_tests
Your job: to make a drawing of this graph and find at least 3 differences between men and women. Note! If you're using Google Chrome, you may need the latest plugin (it's safe to install).
You can also go to this site to get a printable version, but you **must** turn in your **own** diagram of this test. http://en.wikipedia.org/wiki/File:Blood_values_for_print.png

Making the (almost) perfect square wave. Can it be done?

Continue adding up sine waves until you get an almost perfect square wave.
Try changing the number of terms that make up the sum. Move the mouse over the sines/cosines to see each frequency's contribution to the sum.
Try also changing the playing frequency (with your computer's sound ON)
Go to this site: http://www.falstad.com/fourier/e-square.html

11 February 2010

The pH of life

Note how narrow is the pH range of life for humans!
See this link on the effect of acid rain on the pH of lakes, and how this affects the fish's ability to survive:

Adding sines together to make a square wave

See this site to see how to add sine waves to make a square wave:

09 February 2010

Trig functions: SINE

Waves can be built up from a sum of sine functions, of the form: y = A*sin B(x-C).
What does the graph of A*sin B(x-C) look like? See this website to find out:

04 February 2010

pH and acid rain around the US

Check out the USGS (United States Geological Survey) site regarding the effects of pH and acid rain on fish reproduction.  See: http://ga.water.usgs.gov/edu/phdiagram.html