Wednesday Sept 26 (i know im kinda late sorry)

On Wednesday we had a substitute and his name was Mr. Whiteway (he was a English teacher so he wasn't much help). We received 2 handouts on Refraction. One was about how light refracted and the other was exercises on Refraction.

Friday September 29

Hi, I'm Thi and I'll be scribing for Friday's Class. On Friday, we watched a video disk on interference of two circular waves and Diffraction. Note: I put diffraction in bold and Italics because it may be on a test. Diffraction occurs when a wave, for example, made in a ripple tank hits an obstacle. Although the wave may reflect, it will also pass through the barrier at its ends. This causes the wave to slightly bend and is known as diffraction. Diffraction can change a straight wave into almost a circular wave.

When two identical waves that are produced by two point sources collide, they interference with one another. This results in crests overlapping crests, troughs on troughs and even crests on troughs. Areas of destructive interference and constructive interference are created. As shown in the Waves in Two Dimensions booklet and the assignment we received, dotted lines are correspondent with the troughs, solid lines with crests and the grey area is the path of the nodal lines.

Page 17 of the booklet displays what this looks like and explains everything I just said and more.Click to see Page 17

After that we received a worksheet on interference and that is basically all I can remember of Friday's Class.


Since I am the last one to scribe, I guess I have the honour of choosing the next scribe. The next scribe shall be Kevin! For future references, I stink at blogging and this is goodbye for now.

Refraction Worksheet

Hey this is Eric, and I'm today's scribe.

Today in class we watched a video of a crazy teacher who explained waves in two dimensions: reflection and refraction. We also got a worksheet to fill out while we watched the video.

After that, we looked over the answers, which everyone should have since we did them in class.

We then went over the answers for last week's homework, which was:
Questions 5 to 8 in the green booklet

Answers:

Finally, we got an assignment on Refraction that doesn't have to be done for tomorrow, but it would be good if you did some. Also, don't forget to do your research projects!

That's all for today, and the next scribe is Melissa since the scribe today was actually supposed to be her

Hello. This is lauressa.

Well today in class we went over page 12 in our green booklet; waves in two dimensions, and learned about Snell's Law. Snell's Law shows that the ratio of the sine of the angle of incidence and the sine of the angle of refraction is a constant. The constant we use in Snell's Law is referred to as the index of refraction. With Snell's Law it can be used to determine a number of things, for instance the speeds and the wavelengths of incident or refracted waves by this equation

For those who aren't quite sure what refraction is it occurs when waves approach a boundary between two water depths at an angle causing the direction of travel of the refracted waves change. Since the value of n are ratio it doesn't have any specific unit of measurement, but the value of n, is specific for certain materials like air, glass, and water. For Snell's Law we also used old equations but with a little twist. As we all know velocity V, can be found by multiplying frequency F x wavelength λ. Well we can use that equation for help with Snell's Law by putting deep .vs. shallow in front the the characters to solve for the velocity of the deep and shallow water.

After we learned about Snell's law Ms.K handed out an assignment to test how much we could put our knowledge to use. Here was the example questions and the answers if you didn't manage to get them in class.

A water wave of frequency 10.0Hz and speed 40cm/s is traveling in deep water. It then moves into shallow water where its speed is 30cm/s. The angle of refraction is 30°

Find
A) The index of refraction
n=Vdeep /V shallow

n=(40cm/s)/(30cm/s)

n=1.33

B) The wavelengths in the two media

Deep
λdeep=Vdeep/F

=(40cm/s)/10.0Hz

λdeep=4cm

Shallow
λshallow=Vshallow/F

=(30cm/s)/10.0Hz

λshallow=3cm

C)the angle of refraction in the shallow water.
For this question there is more than one way to solve it .

~solution 1~
n=sinθi/sinθr

sinθr=sin30°/1.33

sinθr=0.375 or 22°


~solution 2~
sinθi/sinθr=Vi/Vr

sinθr=(sinθi x Vr)/Vi

=(sin30° x 30cm/s)/(40cm/s)

sinθr=0.375 or 22°


~solution 3~
sinθi/sinθr=λdeep/λshallow

sinθr=(sinθi x λshallow)/λdeep

=(sin30° x 3 cm)/4cm

sinθr=0.375 or 22°

Well that was pretty much it for our class on Friday, but for those who haven't already, the assignment for the week were questions 5-8 in our green booklet, and our wave research project is due on Tuesday. See you all on Monday!!
O yea the next scribe is Melissa

If you're thinking you should realize that question #6 is a repeat of the question we did on the whiteboard.

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.

Straight Barrier: Wavefront

Hello everyone, this is Lina with today's scribe post.


We started today's class by going over the worksheet we recieved yesterday about wavefronts and wave rays. It was pretty straight forward.


Here are a couple of definitions for you:

A wavefront is a continuous crest or trough.
A wave ray is to show the direction of travel/transmission of the wavefront.
Remember: The wave ray is always perpendicular to the wavefront. You can also say that the wave ray is at a right angle to the wavefront.

For the wavefront exercise we had to draw the wave rays of circular, straight and irregular wavefronts.

We continued our unit, Waves in Two Dimensions. How exciting. Below is a diagram of how you would determine how the wavefronts are reflected at an angle to a straight barrier.

A few points to remember about this diagram are:

• The Incident wave ray is perpendicular to the Incident wavefront
• The Reflected wave ray is perpendicular to the Reflected wavefront.
• The normal is the straight line perpendicular to the barrier. (not in my diagram, but please bear with me)
• The angle of incidence (theta i) is the angle between the incident wave front and the barrier.
• The angle of reflection (theta r) is the angle between the reflected wavefront and the barrier.
• The angle of incidence is equal to the angle of reflection.
• Another thing you must remember is that the length between the lines of each wavefront should be equal in distance.

The diagram I drew above uses the angle of incidence and reflection as applied to the wavefronts to determine how the wavefronts are reflected.

Another method is to use the angle of incidence and reflection as applied to the normal. Therefore, the angle of incidence (theta i) would be the angle between the incident wave and the normal and the angle of reflection (theta r) would be between the reflection wave and the normal. I don't think we've used this method as of yet, but maybe we might later on.

We also looked at the reflection of waves from a Parabolic Reflector. We worked on drawing our own diagrams during the latter half of the class. We applied our knowledge of the straight barrier to help us out. The only difference is that it's a parabolic barrier.

Tonight's homework is our very first assignment in Waves of Two Dimensions. Complete it for tomorrow's class (or at least try to). ALSO don't forget our WAVES RESEARCH PROJECT due on September 25. Try not to leave it until the last moment like I know we've all done with one project or another. Good luck on that!

If you find anything confusing or anything wrong. Please leave a comment and let me know. This is my first time blogging for school where someone has to learn from it! I hope I didn't make any mistakes.

Last but not least, tomorrow's scribe will be... Mary Ann.

9/18/07

hello my name is Jennifer I am today's scribe.


Today we had a TEST on Waves In One Dimension 0_0
After the test we got a new green booklet called Waves in Two Dimensions & read up to page 6 we also got an exercise on Wavefront's to finish by tomorrow. That is all we did today (:


finally the scribe for tomorrow is . . .
LINA

September 17, 2007

Hello, my name is Kimberley and I am today's scribe.

Today in class we went over the answers to questions 6 - 14 in the green booklet. If you missed any of the answers, they have all been posted on the blog by Mrs. Kozoriz. For the remainder of the class we worked on a worksheet having to do with Superposition, which you can hand in tomorrow if you haven't already handed it in today.

REMINDER: Tomorrow we have a test on Waves in One Dimension. I would suggest looking over everything in the green booklet. Good luck and don't forget to study.

That is pretty much everything we did today. The scribe for tomorrow is Jennifer.

Problems 6 - 14

Hi everyone! I'm Christine and I will be your scribe for today.

In todays class, we worked on CHAPTER 14: STUDY GUIDE worksheet that was handed out by the substitute teacher. And we also corrected them in the end of the class. Here are the answers for the people who didn't get all the answers.

14.1 Wave Properties

Types of Waves

1. mechanical
   
2. material
   
3. electromagnetic
   
4. no


5. particles


6. matter


7. three


8. perpendicular


9. motion


10. parallel


11. motion


12. surface


13. parallel


14. perpendicular


15. single


16. continous


17. vibrating


18. harmonic

The Measures of a Wave: Frequency, Wavelength, and Velocity

1. shortest
   
2. motion


3. vibration


4. second


5. hertz


6. Hz


7. f= 1/T


8. T


9. f


10. wavelength


11. lambda


12. high


13. low


14. v=lambda(frequency)
    

Amplitude of a Wave

1. maximum


2. equillibrium


3. more


4. energy
   

14.2 Wave Interference

Waves at Boundaries Between Media

1. amplitude


2. frequency


3. properties


4. the same as


5. equal to


6. incident


7. transmitted


8. energy


9. reflected


10. most


11. little
    
12. inverted


13. errect?


14. frequency


15. wavelength


16. speed
    

Superposition of Waves

1. independently


2. displacement


3. sum


4. displacement


5. superposition


6. the same


7. greater


8. shape


9. size


10. opposite


11. zero


12. destructive interference
    

Standing Waves

1. undisturb


2. destructive


3. displacement


4. constructive


5. standing


6. stationary
   
7. standing still

And thats all for the worksheet. Make sure that you have the right answers.

For homework,make sure that you finish questions 6-14 from the green booklet. And also, dont forget to study for the test on Tuesday, Septemeber 18th.

And that was today's class. The next scribe will be... KIMBERLEY

September 13 2007

Hi i am Richard and today i am the fifth period physics class scribe

Today we corrected the Chapter 14: Vocabulary review work sheet. If you did not get all the answers or any of the answers here they are;

1.Standing wave
2.Period
3.Destructive interference
4.Node
5.Amplitude
6.Normal
7. Principle of superposition
8.Transverse wave
9.antinode
10.Frequency
11.Interference
12.Wave length
13.Angle of incidence
14.surface wave
15.constructive interference
16.Trough
17.Diffraction
18.Angle of reflection
19.Longitudinal wave
20.Wave Pules
21.Refraction
22.traveling wave
23.Crest
24.Law of reflection


Then we went through the Green booklet. We looked over these sections

D. Reflection
E. Wave Transmission in Two Media
F. wave transmission and Partial Reflection in Two Media
G. Wave interference and the Principle of superposition
I. Standing waves: The formation of a nodes


After that we went over question 1 - 5 in the green booklet if you missed the answers here they are:

1. Longitudinal and Transverse Wave
2. f = 10 crest
. --------- = 0.1 Hz
. 100s


3. f = 580 kHz = 580 x 10 ^3
. v = 3 x 10 ^ 8 m/s
. Wavelength = ?
. v = f (wavelength)
. wavelength = v 3 x 10^8 m/s
. --- = --------------
. f 580 x 10^3 Hz
. Wavelenght = 520m

4. Wavelength = 2.5 cm = 2.5 x 10 ^-2m
. v = 1470 m/s
. t = ?
. v = wavelength/ t
. t = wavelength 2.5 x 10^2 m
. ------------ = --------------- = 1.7 x 10 ^-5 s
. v 1470 m/s

5. v = 450 m/s wavelength = 0.18 m A = 2.0 mm

a)

b) f = v 450 m/s
. --- = ---------
. wavelength 0.18m
. f = 2500 hz

c) T = 1/2500 = t x 10 ^ - 4 s

d) 1 km = 1000m/8 x 10 ^ -3m = 1.25 x 10 6 5 cycles / km

e) t = 1.25 x 10 6 5 cycles x 4 x 10 ^ -4s
. -------------
. cycles
. t = 50 s


After all that we should Finnish questions 6 - 14 in the green booklet


Welll That's what we did in class today and the next scribe will be .. christine d. ...

Scribe Log 09/12/07

Yet again, another exciting day of physics has elapsed. Of course, with the ending of another physics class comes a new daily scribe. That scribe happens to be me today. Yay! Lets start!

At the beginning of class, we went over the lab that was presented yesterday. The lab was called "Waves On a Snakey". We were grouped into a team of four. Each group was handed a slinky. With the slinky, we had to create waves. Then, we recorded how long it would take for the wave to reach the other end and back. The sheet will explain the rest. For those of you who missed out, I'll upload the lab.

Chapter 14 - Lab Worksheet || Click Here!

After we corrected the lab, we watched a video. The video demonstrated effects of waves, when they are created in different circumstances. The video showed what would happen if two waves collided, the reaction that occurs when the wave pulses are displaced, and a lot of other interesting things. A worksheet was handed out after the video was completed.

18 - Transparency Worksheet || Click Here!

Near the end of the class, a vocabulary review was handed out. I'll upload it for those of you who missed it.

Chapter 14 - Vocabulary Review || Front - Click Here! -- Back - Click Here!

Here are some final notes. A test was announced for Monday. Study hard everyone! Also, the next scribe will be...RichardG.

18 Wave Properties Transparency

Transverse Waves with a Slinky

Hey, I'm Benofschool and I will be you scribe for today.

Today in class we all started on an experiment with slinkys. We used Slinkys to create transverse waves to test out a number of experiments by swinging the slinky between 2 people with another two timing and observing.. The experiments included seeing if the amplitude of the waves have a relationship with the speed of the waves, seeing if the amplitude and the speed remains the same throughout the wave. According to Ms.K this was a very frustrating experiment due to the morning class's complaints. The teacher was right. Timing the waves were really difficult do to coordination issues. Too bad we are humans, we cause human errors.

This concludes my scribe for today and homework is to finish the experiment sheet Ms.K gave us and it is due tomorrow.

The next scribe will be "Thang N."

Bye Y'all

Wave Velocity & Longitudinal Waves

Received PHYSICS 11 FORMULAE sheet.
---

CHARACTERISTICS OF WAVES ANSWER KEY
1. C, A, D, B
2. frequency
3. frequency x wavelength
4. 5 metres, 1.5 waves per second, 7.5 metres, 7.5
---

VIBRATIONS AND WAVES ANSWER KEY
1. 6.5 cm, 1.5 cm
2. 0.5 hertz, 2 seconds
3. 0.002, 0.125
4. 600 Hz, 0.57 m
5. 30 m, distance decreases
6. 30 cm, wavelength decreases
7. 2 m/s, 1 s
8. 5 m/s, 0.5 s
9. high pitched, low pitched
10. wave frequency
---

Read C. Longitudinal Waves in your booklet.
---

Homework: Wave Problems #1-5 (page 12)

Next scribe is: benofschool

Types of Waves

FISRT SCRIBE, "WAVES"

Hello fellow physics classmates,
I am Sam and I will be scribing for Fridays class. We started off by looking at how waves are made and key terms. We were given booklets out that had key terms and some formulas. We learned that a continuous or periodic wave is produced by a disturbance that is moving back and fourth continuously, that is the source is oscillating or vibrating.
click HERE to see the key terms of a wave.

To find the frequency of a wave its,
frequency = oscillations/ time
The period is the inverse of the frequency,
Time = 1/frequency.

We also had a handout to do, which we already corrected in class. We were also given another handout, I guess it was for homework because we didn't really have time to do it in class. The second sheet is CHARACTERISTICS OF WAVES. make sure you finish it for class :)

and there you have it, Fridays class. The next scribe will be

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ZEPH!

Scribe List

This is The Scribe List. Every possible scribe in our class is listed here. This list will be updated every day. If you see someone's name crossed off on this list then you CANNOT choose them as the scribe for the next class.

This post can be quickly accessed from the [Links] list over there on the right hand sidebar. Check here before you choose a scribe for tomorrow's class when it is your turn to do so.

Mary Ann Kimberley lauressa Thang N lina Sangiie

Anh Thi DUONG SAM christine d kristina Richard G

Cow Milk nounith1 ERICT -zeph benofschool

Jennifer H2O Kevin melissa

Frequency and Period Relationship