Thursday, September 20, 2007

Waves Moving From One Depth to Another & Refractions

Hello! This is Mary Ann.

In class today, we got our assignments and test back. We went over the answers for the test, so if you missed any of them..here they are!

1.


This is a transverse wave.


2. amplitude = 1.5 cm
wavelength = 4.5 cm


3. a. longitudinal
b. (i) compression
(ii) rarefaction
(iii) wavelength


4. a. f = 50/10 = 5Hz
b. T = 1/5 = 0.2s


5.
The wave should appear inverted since it hits a fixed end.

6. This is how your diagrams should have turned out.




7.


8.



9. Constructive Interference: occurs when two pulses on the same side pass through each other. This causes the amplitude to increase.
Destructive Interference: occurs when two pulses on opposite sides cancel when overlapped.

10. The main function of a wave is to transfer energy through a medium.

11. a) true
b) meters or cm
c) true
d) normal
e) transverse

12. A standing wave consists of two waves of equal amplitude, frequency and wavelength.





The red dots represent the nodes. The blue dots represent the anti nodes.

After making corrections on the test, we looked into the green booklet on page 9-11 and learned about
Waves Moving From One Depth to Another & REFRACTIONS.


When waves move from one depth to another, the frequency does not change. What changes is the speed of the waves. In deep water, the speed of the waves is vdeep = (fdeep)(λdeep). The speed of the waves in shallow water is vshallow = (fshallow)(λshallow). Since the two frequencies are the same it can also be written as vdeep/vshallow = λdeep/λshallow.


In this picture it shows a straw in a glass of water that appears to be broken but it is actually being refracted since half of it is in water and the other in air. Air and water are the two mediums in this case.

*NOTE*
-The 5 questions on Waves in Two Dimensions - Assignment 1 is due tomorrow.
-Our project is due on Tuesday, September 25th.


The next scribe is going to be LAURESSA.

6 comments:

Anonymous said...

good scribe mary ann!
HA-HA stinky lauressa is scribe tomorrow. alright (y)

Mary Ann said...

thanks samus!

Ms K said...

Great scribing Mary Ann. Really like the picture of the straw in the water.

Mary Ann said...

thank you ms k!

Darren Kuropatwa said...

Hey Mary Ann. That pic is great! The entire scribe post is wonderful but it's been a while since I studied any physics. The picture really helped me "get it." Thanks! And keep up the excellent scribing. ;-)

Cheers!

m@rk said...

Good scribe Mary Ann!!! It somehow feel like that i was a part of your class.Great detail on the answers from the test too.