March 24 & 25

For these two days, we didn't do very much. On March 24th, we got our tests and labs back from Mr. Vincent, who then proceeded to give us corrections for both of them [the answers for the bonus questions were radial and coridal artery, by the way.]. Also, for those who missed their lunches during the talent show, we were given a chance to get our food and eat in class, as long as we didn't make a mess.

On March 25, we spent our final day before spring break watching an episode of Mythbusters, specifically the episode where they prove whether a lead balloon was possible, and if a wave caused by TNT can be surfed successfully. For those who don't mind spoilers, the results were "confirmed" and busted" in that order, respectively. There was also a plate of chips left out for anyone wanting a snack, but it was left untouched, I believe. That is all.

The next scribe shall be keinaan94. And yes, I am aware that my scribe is late, and I apologize for that.

March 23, 2011

Okay, so we didn't really do anything serious today. We got to class, sat down, and started writing a test for our unit about 1D waves. I hope I did well, I think the class did okay. So if you missed the test, plan some time to make up for it. There was no homework so I really don't know how to drag this scribe out any longer...

Well, yeah Jackson will scribe tomorrow!
byee!~

What we did today..

Well, today we just watched a short video that described almost everything that we've been looking at regarding the springs. The video showed transverse waves, longitudinal waves, reflected waves, transmitted waves and anything else that you could think of.
After that, we played jeopardy for the rest of class and that involved prizes! Too bad we didn't win any.... The jeopardy was to help review and study before the big test tomorrow. The test format will be something like this:

Part A (12 marks)

• Multiple choice and definitions

Part B (11 marks)

• Concepts and visuals

Part C (13 marks)

• Calculations

BONUS: 1 mark
TOTAL: 36 marks possible

Too bad I didn't put this up sooner for people who wanted to see the format.. Oh well!
Good luck studying anyways!
Jenna will be the next scribe (:

March 21, 2011: Constructive and Destructive Waves

Hello fellow classmates, so for scribing late today I needed to do some intense studying since my period two (intense homework period) was spent in the gym riot/pep rally. We started the class off with Mr. Vincent giving us new notes about wave interference. He also took attendance. After attendance we went outside to see a demonstration about wave interference and reviewed the types of waves that we have already learned. First Mr. Vincent and helper used the small denser spring to knock over a Styrofoam cup, things got more interesting when bricks were put on both sides of the cup so that the single wave produced by the spring wouldn't be able to hit the cup. Mr. Vincent and helper then timed their waves so that they will collide where the cup is between the bricks to produce a larger wave that will hit the cup. This type of wave produced is called a constructive wave. We went inside to go over the notes and learned how to draw constructive and destructive waves and were assigned the last page, Appendix 1.4: Waves in One Dimension, to complete as homework. Then we went outside again with the big spring to see how destructive waves work. Mr. Vincent told the helper to try and hit the cup that was placed midway of the spring, as he tried and tried Mr. Vincent kept creating an opposite pulse that was perfectly timed to meet up with helper's wave so that the amplitude was 0 and the cup would not be hit. Then Mr. Vincent showed us what a sound wave looks like. Then we went back in class to work on homework which we will go over tomorrow. Wednesday is our test so study that formula! Alright bai guys! Next scribe shall be David.

Answers from page 13.

Here are the answers for the "physics of a wave on a string question". Hope you all had a good weekend.

Mr V

a) (1 mark)

For each complete wave cycle of the wave, a particle on the string moves a total distance of 4A where A is the amplitude of the wave.

The total distance moved by the particle is 4(2.0 mm) = 8.0 mm.

b) (1 mark)

The frequency of the wave is 2500 Hz

c) (1 mark)

The period of motion is the inverse of the frequency: 4.0 x 10^-4 s

d) (1 mark)

For each second, or one period of motion of the wave, the vertical distance travelled by the particle is 8.0 mm or 0.0080 m. To travel a distance of 1.0 km, the number of cycles of the wave (or periods of motion) is

number of cycles = 1.25 x 10⁵ cycles

e) (1 mark)

The total time required is

t = (1.25 x 10⁵ cycles)(4.0 x 10^-4 s/cycle) = 5.0 x 10¹ s

Reflection and Transmission of Pulses and Waves

We started off the class with the answers given on the whiteboard from the homework we were assigned to finish the previous day; Describing Waves Assignment #12-16 and page 13 in our handouts #1-2.

Here are the answers you can refer to in case you missed today's class:

Describing Waves
12) D
13) V = λ/T or V = λf
14) 2 m/s
15) 24.2 m
16) 5 s

*For question 16, a few of us got the answer 2 s. I do not think Mr. Vincent heard us ask about it so may you please go over it on Monday?

Page 13
1) 5.2 x 10² m
2) 1.7 x 10^-5 s

We then moved onto Wave Reflections and Wave Transmissions where we experimented with two types of springs; a light medium spring and a heavy medium spring.

We all went in the hallway and watched the reflection pulse of the light medium and heavy medium spring. We learned that when we gave the spring a wave, once the pulse reached the barrier, the rope exerted a force upward on the support. This support then exerted an equal but opposite force downward on the rope. This downward force on the rope is what causes the pulse to reflect back on the opposite side, or inverted. This can be related to Newton's Third Law where; every action has an equal and opposite reaction.

From a free end of a spring, meaning there is no solid barrier at the end, once the pulse reaches the end of the spring, the particles exert an upward pull on the end of the rope which generates a reflected pulse that is now on the same side of the rope as the incoming pulse.

A reflection can be defined as the return of a pulse or wave from the boundary of a medium.

Next was Wave Transmission in Two Media, where we taped together the two different springs. We then tested out what happens to the waves as the two are taped together. We learned that when a wave passes from a fast medium into a slow medium, the particles in the slower medium have greater inertia. The reflected wave is inverted where the transmitted wave is not inverted.

A partial reflection is when a wave moves from one medium to another, some reflection occurs at the boundary between the two media, where some of the energy is transmitted into the new medium and some is reflected back into the original medium.

We then went back to class and drew diagrams of these different types of waves we saw because by the end of this lesson, we should be able to draw transmission and partial reflection of pulses and describe how pulses or waves in one dimension are reflected from a fixed end and a free end. I will attach photos of how the diagrams look like somewhere on this post since I cannot move the image..

There was a remaining 20 minutes of class when we received our next few pages of notes, pages #17-26. These pages should explain everything about the Reflection and Transmission of Pulses and Waves that we learned today.

For homework, we were assigned to finish any questions given in the pages #17-26. This is suppose to help us review for the test we have on Wednesday!

Last but not least, 7evin shall be the scribe for Monday's class. I hope this did not bore any of you..just wanted to cover everything! Have a great weekend.

Dynamics Test Answers

Manipulating Period and Frequency

For today's class we first started by correcting question 1-5 of the sheet "Describing Waves"

Here are the following answers just in cased some of you guys missed it:

1. Crests: B,E Troughs: D,G Neither: A,C,F,I,H,J

2. A is the wavelength and D is the amplitude

3. a) 3.9 b) 0.8 (it doesn't matter if your off by a bit)

4. frequency

5. a) 1/60 hz

After the worksheet corrections we were assigned to do a lab "Manipulating Period and Frequency"

For the lab we were supposed to be in pairs or in a group of 3, we first had to answer question 1-3 of the sheet (worth 3 marks) after answering the questions the procedure of the lab is at the back of the paper.

- we had to measure our pulse for 30s: first in a calm environment and then a measure of our pulse after a light activity such as running up the stairs 3-4 times.

- then we had to figure out the bpm, frequency and the period

- After measuring our pulse we then had a chance to experiment with the pendulum (the strings hanging from the ceiling with a small weight attached at the bottom)

- For the experiment the bob (mass) is pulled one meter horizontally from where it is hanging

- We then release the bob and it starts swinging back and forth

- Count 15 full oscillation timing it, record your trials (you need 3 trials) and fill in the frequency and period of each trial.

- After the pendulum experiment we then moved on to one of the hanging mass on a spring apparatuses

- We pull the mass 15 cm below its equilibrium point

- Let go and count 15 full oscillations and record the time

- You'll need three trials, and after you've gotten your recored time fill in the frequency and period

Well.. thats pretty much what we did today. LABS ARE DUE FRIDAY! and we got our test back

- PAR

Waves in One Dimension

In today's class, Mr. Vincent started teaching us about waves as it will be our new unit. He handed out papers that explained everything about waves and went through it all with us. We learnt that a wave is a disturbance that transfers energy from one place to another. One of the waves we learnt today is called a transverse (periodic) wave - produced by a disturbance that is moving back and forth continuously. The other wave is called a longitudinal (compressional) wave - the vibration of particles that travel the same direction as the motion of the wave. Waves have a pulse which is a single wave bump, they have crests which are the high points on a wave, troughs are the low points of a wave, and the amplitude of a wave is the maximum height between the top of a crest or bottom of the trough to the middle (particle's undisturbed position). Each wave also has a frequency - how many complete cycles (or crests) past a point per unit of time - which is measured in hertz (Hz), and a wavelength - distance from one crest to another or one trough to another. A period in a wave is the time elapsed between two successive crests passing by the same point in space and a cycle is how many times the particle does a complete oscillation (particle moving up & down or left to right) once.

Mr. Vincent then gave us a worksheet that helped us "describe waves" - learn the wave basics. We did questions 1-5 on the worksheet. We are doing a lab in tomorrow's class. & one last thing PAR will be the next to scribe :) hope this was a good scribe for my first time :) bye!

Last person to scribe this session is Paula!

March 9, '11 - Dynamics - Vectors

Today we started off by correcting the lilac coloured sheet "Grade 11 Physics: Dynamics-Vectors". Remember that you have to include the direction or unit in the answer or you'll lose marks. Then we went over the backside of the page, and the practice questions are for homework and we'll go over them tomorrow.
1. A boat aims itself due east at 15km/h across a northern current of 5.0km/h. What is the boat's resulting velocity?
2. What is a ball's actual velocity if after 2 seconds in the air, it has a Vy = 20m/s up and Vx = 10m/s?
3. What is a kite surfer's velocity if the waves are moving him East at 1.5m/s and the wind is blowing him North at 4m/s?

After we corrected questions 1-5 on Newton's Second Law (page 43) of the Dynamics booklet, and if you haven't finished questions 6-9 have them done for tomorrow. Then Ms K assigned pages 12 (Net Force) and 33 (Transparency 4-4 Weight and Normal Force) in the Dynamics booklet to be done for tomorrow as well.

If you need a protractor you can buy one from Ms K for $1. And don't forget the test on Friday!
BryanC to scribe next

Tuesday, March 8, 2011.

Salutations.

In today's wonderful class we went over our assigned homework pages in our Dynamics booklets. We went over the answers of page 31, "Transparency 4-2 Worksheet" and how it was done. Don't forget to convert what you're given (km/h to m/s, and hours to seconds) to fully answer what the question asks for. Unfortunately I left to go to the washroom at the end of this page, and came back when we had to work on the new sheets. If someone would please enlighten me on what went on during my absence and leave it in the comments below for everyone to view, that would be greatly appreciated.

Continuing on with the second half of class, we were given two sheets labeled "Dynamics-Vectors" which was for practice, and "Forces in Two Dimensions" which was to be handed in. We were to plot the vector of the plane's velocity on the graph provided.

• The questions asks that you first decide on a scale, in which case [1cm = 10m/s] was recommended. Also label the directions (north, south, etc.) but I bet you already knew that.
• The next step would be to take your protractor, starting at the origin, and place a line 30 degrees to the north of east direction.
• If you did this correctly to the scale recommended, you will have a 6cm line (because the velocity is 60 m/s) with an arrow at the end because it is a vector. Place your protractor on top to make sure it is aligned with the 30 degree mark.
• Next you were to add another vector, representing the velocity of the wind that "blows on the airplane with a speed of 8m/s going in the direction 75 degrees south of west in the same way." Again, line it up with your protractor to make sure it is accurate.
• The resultant line would be the line connecting the origin to the head of the wind vector.
• The last part was to answer the few questions on the back, which deals with the beautiful diagram you just created.

I assume this should be finished by tomorrow's class. A reminder to bring your own protractor to avoid the unlikely event of having to buy one as I did. If there's anything I missed, comment below!

Don't forget the test on Friday! Have a wonderful evening, the next scribe shall be justing.

DYNAMICS in miss k's class

well today in physics we had to hand in our lab graph which we did on friday plus we have a dynamics test friday so remember to study! today mrs.k forced us to work in our dynamic booklets on page 30 31 and 43 .since im such a nice guy ill post our force notes up here.our precious notes included Fa:friction between snow and sled
Fb:pull of person on sled
Fc:tension between sled and rope
Fd:pull of rope by person
Fe:pull of sled by person
Fd:friction between person and ground
oh yea the pages that should be completed for tomorrow are 30 31 and 43
and before i forget mrs.k wants us to bring a protractor to class tomorrow due to a assignment shes assigning us to do.

i proclaim the next scribe to be bobthebuildeder
lets see if he can fix it. =D

Friday, March 4th 2011

Last Friday, in the beginning of our physics class, we received our movie assignment back (the one called Newton's 1st Law by Paul Hewitt, where we had to write down seven physics facts that we liked.). Then we went over the free body diagrams in our book, we finished the questions on page 41 and 42 (note: Static means not moving, and if a ball is on an incline slope the normal force exerted from the surface the ball is on, would be perpindicular to the incline). Then we finished up the lab, and it may be handed in by next Monday. Keep up the good work!

The next scribe for next class would be the one and only ahmed rage!

March 3, 2011 - Force and Acceleration Lab

For today's class, we started off by doing the lab or experiment about force and acceleration. As we have learned yesterday from the video by Paul Hewitt about Newton's first law of motion, which states that "when no net external force is acting on an object it will either remain at rest or, if it is moving, it will continue to move in a straight line at constant velocity". We will have to apply what we've learned from recent lessons for this lab.

We started the lab by preparing the equipments needed such as laboratory cart, recording timer, carbon paper discs, pulley, large paper clip, washers, and heavy strings. After that we follow the procedures in the lab handout(if you don't have one, please ask Ms. K for a copy). Make a data table, record your results, sketch a graph for your results and I think we have to answer the Interpretation in the worksheet. Don't worry, Ms. K told us that we still have some class time to finish the lab for tomorrow.

Definition:

Tock - is the distance between two consecutive numbered dots represents one time interval.

Things to remember:

          1. Test the sys. to see if you have offset friction. (Hint: put enough washers on big paperclip to offset friction)

          2. Label 5 tapes as 50g, 100g, 150g, 200g and 250g. Tapes should measure 1.0 metre long.

          3.Data table 7 - 1 needs to be extend(1-16) for tape 1 and 2. This means you need more than 10 entries for 2 tapes.

I think that's all, the one who will scribe for tomorrow's class is Keinaan94.

Newton's 1st Law - Paul Hewitt and Free-Body Diagram for objects on an Inclined Surface.

Definition: For Today Class!

Newton First Law: The law that a particle not subjected to external forces remains at rest or moves with constant speed in a straight line.

Force: Push or Pull.

Inertia: The ability of an object to resist changes in its state of motion is a fundamental property of all matter

Weight: The force that gravity exerts on an object due to its mass [SI unit is the Newton]

Mass: the quantity of matter an object contains [SI unit is the kilogram]

Gravitational force: is an attraction between two objects because of their mass

Friction: A force opposing the relative motion of two objects that are in contact.

We started the class by watching video, the video that Mrs. K wants to show us last week. The title of the video is Newton’s 1^st law by Paul Hewitt. Our task for the class today is to understand the video and Write down 7 interesting that you learned in the video. The summary of the video are about Inertia, force, gravitational force, mass, weight, velocity, and acceleration. Also, from the video they talk about the homework last week on the book Pg.37 # 1. After we done watching video we continue to talk about the free –body diagram for objects on an inclined surface (page 17 # 7 & 8).

Mrs.K wants us to answer the FF.

Page 40 (#8,9,10) the one that we skipped last Monday because we did not study the object on an inclined surface.

Page 41 (#1-8)

Page 42 (#9&10)

Lastly Mrs. K said that be prepare for our First lab tomorrow. Read the worksheet that she gave to us (Force and Acceleration).

Have A Nice Evening Everyone :)

Next Scribe : Da5rkmatter