January 14 2009 - YVANNE

Hey guys!

So I know I'm not Lynel Pobre, but she asked me if I can possibly do the scribe for her instead because she's stuck doing a thousand word essay due to procrastination! Good luck to her .

Anyways, there's really not much that we did today. Our whole class was dedicated to writing our Electric and Magnetic Fields test. I guess I'm just here for a couple of reminders and such.

Mrs. K handed out a couple of sheets for Magnetism. We should probably read through the booklet so we have an idea of what this unit will be about. There's also a Study Guide for Magnetism if you guys wanted to start on that (although the answers are in the green book, you can probably find them elsewhere!)

Do not forget our exam date!
Physics 30S Exam: January 26 2009 Monday

I think this is a great time to start looking through everything we've learned so that we do not end up scrambling at crunch time!

going going ... GONE!






ohh the scribe for tomorrow will be.. LORENZ BRUCAL cause he wants extra marks.
buahah . (:

-ydandan

Kinematics

Hello !

Today in class we did quite a bunch of things. One of which was correcting Appendix 3.6: Describing Motion in Various Ways

Appendix 3.6: Describing Motion in Various Ways:

I'm pretty sure that people made some minor mistakes because of the "ohhh!" reactions and "that's how it is!" responses after Mrs. K told us the answers. I think the tricky part of the whole thing was the l ast two questions. (Question 4 letters e and f)

e) What is the total displacement for the student's journey? Find this from the graph.
I'm pretty sure most of got the right numeric answer (5m) but must of us missed the minor things that makes all the difference. First of all, this one needs a direction [south] and since it's going in the southerly direction, it is negative. Therefore you can either put your answer in the form 5m [south] OR -5m to show the negative.

f) What is the average velocity for the whole journey?
Average velocity can be calculated using the formula v = d/t
The tricky part of this question is the same as the last question. Basically the possible minor errors that can occur can lose you a mark!
answer: .1 m/s [s] OR -.1 m/s
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Aside from correcting the worksheet, Mrs. Kozoriz left us with other work to do. Those are all for homework (Position-Time Graphs, Chapter 3 Study Guide and Study Guide 5.1 Graphing Motion in One Dimension)

OUR NEXT SCRIBE IS:: LYNEL POBRE!

Monday, Sept 15 2008

First of all, I am very sorry I just started the blog right now. I just came home from a dance rehersal, I apologize. (: But hey! I'm still in front of my pc doing this awesome blog of mine!

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Today in class we basically went over the study guide given to us on last friday.

It mostly covered the properties of the waves and the wave interferences.

What I will be doing is picking out certain parts under every subtopic that I believe is the most important out of the whole study guide.

WAVE PROPERTIES

Types Of Waves:

Mechanical waves: require a material medium (basically means it is not capable of transmitting

energy through a vacuum/empty space)

: examples - water waves and sound waves

: 3 kinds of mechanical waves - transverse, longitudinal, and surface waves.

electromagnetic waves: requires no medium

: examples - light waves and radio waves
: produced by the vibrations of charged particles

**refer to past posts by past scribes for further detail on transver, longitudinal and surface waves. **

Refresher on measures of a wave:

frequency: number of complete vibrations per second measured at a fixed location (hertz)

period: shortest time interval in which the motion repeats itself

wavelength: shortest distance between points where the wave pattern repeats itself (lambda)

Amplitude Of a Wave:

- it takes more work to produce a wave with a large amplitude than it does to produce a wave with a small amplitude.

therefore: the larger the amplitude, the more energy is transferred.

WAVE INTERFERENCE:

Waves at Boundaries Between Media:

(media is plural for medium)

this subtopic basically covers what happens to waves when we have more than one medium.

**the speed of a mechanical wave does not depend on the amplitude or the frequency of the wave**

Mrs. Kozoriz said that this is a very important thing we need to know so get it stuck in your head!

**the speed of a mechanical wave does not depend on the amplitude or the frequency of the wave**

Got it yet? Let's just have it one more time.

**the speed of a mechanical wave does NOT depend on the amplitude or the frequency of the wave**

Having that said, the speed of a mechanical wave only depends on the properties of the medium.

incident wave: the wave that reaches the bounday between one medium and another.

transmitted wave: the wave that moves through the new medium

reflected wave: the partial wave of the incident wave that moves backward from the boundary

**when a wave passes from a less dense to a more dense medium, the reflected wave is inverted. **
** when a wave passes from a more dense to a less dense medium, the reflected wave is erect, or on the same side.

!CONSIDER THE FOLLOWING!

When a wave is trasnmitted from one medium to another, the frequency of the wave does not change, however the wavelengthe and the speed of the wave changes.

Superposition of Waves:

PRINCIPLE OF SUPERPOSITION: the displacement of a medium caused by two or more waves is the algebraic sum of the displacements caused by the individual waves.

*interference is the result of the suporposition of two or more waves*

*constructive interference occurs when the wave displacements are in the smae direction.

*destructive interference occuse when the wave displacements are in opposite directions.

Standing Waves:

Node - area that is undisturbed (moves the littlest)

antinode - area with maximum displacement

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I think that this is a very interesting topic actually. It's my first time to ever study Physics and I'm actually quite interested in this topic. I just find that it has a looot of information you really need to know, like the parts of the waves, what everything does and how it affects other things. Once you really get to understand everything we cover in class, I think the test will be a alright for us all.!

So that's the end of all of this Physics talk.

AAANNNNDDD! not to forget that we have a very lovely Physics Test dedicated to Waves in One Dimension on Thursday, September 18 2008. So study study study!

The scribe for tomorrow will be CAMY TRAN! (caaamy)

ciiiiiaaaaaoo!!

-yvanne gelli dandan (: