Oh no!

Exams is in two days. Is everyone ready? My tip; study hard, look over the review sheet, all your tests, while taking 15 minute breaks each for each hour, and most of all, get an early nights sleep.

For the class on Thursday and Friday, all we did was study for the exam. However on thursday some of went to the UofM to apply for a scholarship. And in case you didn't know, if anyone has an average of 80% or above in atleast 5 classes from grade 9 to 12 are eligible. The scholarship qualifies not only for the UofM but Red River and UofW aswell. Talk to Mr. Purpur for more details, and be quick with it! First come first serve.

So I just wanted to wish everyone luck on their exams! GOOD LUCK! =)

Electromagnetic Induction Review

review for last fateful test! & CH 26 review

Chapter 26 review worksheet questions # 1-3 ignore 4&5 # 6-9
Answers on smart board

review for last fateful test! study hard everyone!
test out of 30-35 marks on Electromagnetic Induction including magentic flux, radius's, areas and diameters. need to know how to calculate these using the correct formulas.
A= (3.14)R2

Lenz's Law:
Know it!!
coil and magnet example

also need to know what a traansformer is.
Transformer- convert voltages
Pp=Ps means primary power = secondary power
IpVp=IsVs

Good luck on the test tomorrow and the exam next week

Transformers

Answers to Electric Current Test

Scribe

Yay...I beat everyone to it. Today in class we started off with a video on Electromagnetic Induction and Alternating Current. The video was approximately half an hour. As we watched the video we filled out a sheet that was filled with questions about the video and we then went over the answers.

After the video we went over study guide number 25 and 26.

We then went over a worksheet titled Grade 12 Physics Worksheet: Electromagnetic Induction

Here are the questions and answers below
1. An airplane travels 1000 km/h in a region where the earth's field is 5.0 x 10^-5 T and is nearly vertical. What is the potential difference between the wing tips that are 70 m apart?
EMF= Blv
EMF= (5.0 x 10^-5 T )(70 m)(277.78 m/s)
EMF= 0.9722 V
2. A straight conductor 10.0 cm long is moved through a magnetic field perpendicular to the flux at a velocity of 75 cm/s. If the flux density is 0.025 weber/m², what EMF is induced in the conductor?
EMF= 1.8x10^-4 V
3. A rod 15 cm long is perpendicular to a magnetic field of 0.45N/(A)(m), and is moved at right angles to the flux at the rate of 30 cm/s. Find the EMF induced in the rod.
EMF= Blv
EMF= (0.45)(0.015 m)(0.3 m/s)
EMF= o.o2025 V
4. What EMF is induced in a 5.0 cm long wire moving with a speed of 10 cm/s across a field of 0.020 N/(A)(m)?
EMF= Blv
EMF= (0.020)(0.005 m)(0.10 m/s)
EMF= 1x10^-4 V
5. A coil of 325 turns moving perpendicular to the flux in a uniform magnetic field experiences a change in flux linkage of 1.15 x 10^-5 weber in 0.00100 s. What is the induced EMF?
EMF = 3.74 V
6. How many turns are required to produce an induced EMF of 0.25 V for a coil that experiences a change in flux linkage at the rate of 5.0 x 10^-5 weber per second?
50 turns
7. A coil of 75 turns and an area of 4.0 cm² is removed from the gap between the poles of a magnet having a uniform flux density of 1.5 wb/m² in 0.025 s. What voltage is induced across the coil?
1.87 V

Class was almost over so we picked up 3 sheets, 21.2 Lenz's Law, Review chapter 26, and Transformers Chapter 37: Electromagnetic Induction. These sheets are to be done for Monday.

* Make sure you have a Physics Exam Review and the answer key.

I think that's it...so have a good weekend :)

Magnetic Fields

Hello Guys............(english,english).Ok what Ms. K discussed today is all about Magnetic Fields.

-One magnetic line is sometimes called Weber (Wb)

-units of B (magnetic field strength)

One Tesla(T)= one newton/(ampere*meter) or Wb/m²

-One Tesla is about 5 Times the strength of an ordinary bar magnet. The earth's magnetic field is about 5 x 10^-5 T (0.00005)

-when we talked about the number of magnetic lines we use the expression Flux, and designate it by the Greek letter "phi"

Electromagnetic Induction

A current set op in a closed circuit located in a magnetic field whenever the total magnetic flux lining the circuit is changing.

Two conditions necessary for an electric current to be produced with a magnetic field:

1. Must have a closed circuit

2. Must have changing magnetic filed

Three factors that determine the value of the induced EMF are

1. Length of the wire

2. Flux density of the field

3. Speed of which conductor moves through field

and the formula....EMF=Blv

and after discussing all of this Jennie and her friend reported about mars exploration,it was supposed to be like past two months ago..

Next scribe would be.... nivram!!!hahahaah

Circuits Exercises

Hello guys!!!! Remember that we are having a test tomorrow so better read your notes tonight because it will help you have great test results. Back to what this blog is all about, Ms. K discussed the hand-outs she distributed last friday. The answers are posted in her slides. Afterwards, she gave us the answers to the exercises but the solutions are not given because she wants us to solve it ourselves. As a feedback, not giving out the solution is a good way to practice what we have learned because it will help us understand the topic more.
The following is from one of our hand-outs. I posted this because this what we need to remember and understand so that we can solve easy and difficult problems.

SERIES AND PARALLEL CIRCUITS

TYPE
OF CIRCUIT

1) SERIES

CURRENT is constant throughout the entire circuit.

POTENTIAL Individual potential drops add up to the total potential drop.
DIFFERENCE

RESISTANCE R_total= R₁+ R₂+ ....

2) PARALLEL

CURRENT Individual currents add up to the total current.

POTENTIAL Potential difference is constant across all parts of the circuit.
DIFFERENCE

RESISTANCE 1/R= 1/R₁+ 1/R₂+ ....

This table summarizes the basics about the series and parallel circuits so if you master this table, solving problems are not as hard as you think it is.

The next scribe is KEITH!!!!!!!!!!!!!!!!!!!!!

Good luck and Godspeed......(",)!!!!!

Resistivity and Combination Circuits

Resistance and Circuits

May 31, 2007

Things we did in class:



- got our test paper back and corrected it.



- Ms.K handed out a booklet called Kirchoff's Contribution that talks about electric potential, electric potential difference, how to determine the resistance, current, voltage, power for series, parallel, combined networks, Kirchoff's Current Law and kirchoff's Voltage Law.



- a cheat sheet called "Series And Parallel Circuits" that talks about the differences between a series circuit and parallel circuit.



then Ms.K gave us a work sheet to do to test our knowledge and skills..to see if we are really listening and understanding the teachings that she just gave us....~~save by the bell! got only number one on the board...will finish the rest tomorrow...^____^



THE NEXT SCRIBE FOR TOMORROW IS...



JAMIE!!! MWUHAHA!

Test Corrections/Series & Parallel Circuits

New unit

Today in class we went over the questions that we were assigned yesterday in our text books. We got a new sheet on current and another sheet on Cavendish and the first electric meter. Also today in class we got two study guides to do in class. we went over Ch.22 study guide today.
Allen will scribe tomorrow.

Physics Class on May 28, 2007

New Topic: Electric Current

Today's class started off with a video on "Electric Current."

KEY CONCEPTS IN THE VIDEO:

- VOLTAGE = ENERGY (JOULES) / CHARGE (COULOMBS)

- CURRENT proportional to VOLTAGE DIFFERENCE

- CURRENT (AMPHERES) = VOLTAGE DIFFERENCE / RESISTANCE

- I = V / R

- DIRECT CURRENT: A current travelling in ONE direction.

- ALTERNATING CURRENT: A current alternating back and forth.

** Basically the video was an overview on series and parallel circuits.

For the rest of class we were assigned the following:

Read PGS. 469 - 475
Do Practice Problems:
PG. 471 - 472
#1 - #4
PG. 474 - 475
#5 - #8

The next scribe is: GEAR321 (AKA. Eddie)

Sorry i posted this too late, i didn't know i'm supposed to blog last thursday. Well
last thursday Mr. Newman was substituting our class. He assigned our class to answer the " Moving charges worksheet" number 8 to 16 and then we went over the answers. Before the end of the class he gave out 4 handouts for us to do for homework... and that's all i remember.

since someone is chosen to scribe today. i don't have to choose who to scribe next! YEy.

Magnetic force and magnetic field

Ms. Kozoriz is not in class today..so wild cats are everywhere! But Mr. Newman substitute for her on that day!!

Good day everyone..RICARDO is your scribe for today.

First thing he did is... he handed us back the the experiments and assignments.

Then we answer the no. 4 question

(a) Fg and Fe

(b) positive

(c) mg = Eq

q = mg/E

= 1.6 x 10^-18

(d) q = Ne¯

N = q/e¯

= 10e¯

CATHODE RAY TUBE

Electrons leave the cathode and accelerates toward the anodes (p. 536)

The electric field, E, alone produces a force on the electrons Fe = qE causing the electrons to deflect up to x.

The magnetic field, B, alone produces a force on the electrons FB = Bqv causing the electrons to deflect down to y.

(1) To find speed, v, of electrons, adjust B and E until electrons hit point Z

FB = FE

Bqv = qE

v= E/B

(2) To find mass, turn off E. B will deflect electrons to y where

FB = FC

Bqv = mv²/R

m = BqR/v

(3) To find the charge / mass ratio

q/m = v/BR

or

v = E/B

therefore

q/m = E/B²R

In the end of the class..he let us work on questions 8 - 16 in Moving Charges worksheet.

GOOD LUCK to our test on FRIDAY!!!

The next scribe will be...Ms. Makintosh

Review for Friday's Test

Electric and Magnetic Fields

• know the difference between gravitational fields and electric fields
• know the difference between gravitational force and electric force
• what's the diff between a field and a force ?????????
  

HINT: are they vectors? what direction do these vectors take? are masses or charges involved? what are the units for these quantities?

• Coulomb's law - know how to apply it, what constant is used (k=9 x 10⁹),
• what is the relationship between electric force and distance between the charges?
• how is this law similar to Newton's law of gravitation and how is Coulomb's law different from Newton's law of gravitation
• don't forget charges have a unit called the Coulomb;
• charge on a proton is equal to the charge on an electron which is 1.6 x 10^-19

Strength of an Electric Field

• E = F_e /q [field intensity around a test charge; remember a test charge is very tiny and positive]
• E = kq/d² [field intensity due to a single charge]
• E = V/d [field intensity between 2 oppositely charged plates]
• The above 3 formulas all solve for electric field, units being N/C or V/m

Electric Potential/Electric Potential Difference/Electric Potential Energy

• what the heck is potential??? ratio of potential energy per charge
• potential difference is the difference between two potentials-we tend to use potential difference in calculations
• electric potential energy is the amount of energy a charge has due to its position; see the notes on gravitational potential energy and the similarity to understanding e.p. energy
  
• PE = W = qV does this make sense to you? can you explain why potential energy is equal to work????
• know how to solve problems on charged particles that exist between two charged parallel plates (questions 1-4 on Moving Charges worksheet)

Magnetic Fields

• when a charged particle enters a magnetic field its direction changes; an electron will circle one way and a proton will circle in the opposite way
• a magnetic field only changes the direction of a charged particle where an electric field accelerates a charges particle [nice to know this difference]
• the magnetic force acting on a charged particle is given by the formula F_B= Bqv, where B is the magnetic field (measured in teslas), q is the charge (measured in coulombs) and v is the velocity of the charged particle (measured in m/s)
• when a charged particle enters a magnetic field, the magnetic force acting on this charged particle is equal to the centripetal force acting; we can equate these two formulae to solve for unknowns.

F_B= Bqv F_c= mv²/R

F_B = F_c, therefore,

Bqv = mv²/R

Bq = mv/R

m = BqR/v let's you solve for the mass of the charged particle

You can rearrange this formula to solve for the radius of curvature, magnetic field, velocity, etc
See problems 8 - 16 on the Moving Charges worksheet that deal with these formulae given above.

Technologies that use combined electric and magnetic fields are older type of televisions that have a cathode ray tube [not plasmas or LCD TV's], mass spectrometers, loudspeakers-think of objects that have magnets and electric currents.

May 22 2007

we started off with question #7 on the test corrections...
next Mrs.K handed out a booklet which she read over to us...I suggest you read it...its very important.
Then we were assigned questions which she also handed out..."Moving Charges Worksheet"
do questions 1-16 but omit 5 6 and 7

the answers to:
1a) Fg is greater than Fe therefore the drop falls.
b) 3.45 x 10^-4 N [down]

2) 4.6 x 10⁶ m/s

3)2.24 x 10^-13 N (down)

next scribe will be ricardo...

scribe post - lindsay

This is Lindsay scribing for Thursday's class.

We first watched a video on electric fields. Here are the answers from the handout:

1. charge, potential, field
2. determine height above sea levels
3. field lines
4. hard
5. no
6. down
7. elevation; downward slope
8. E=-v/R
9. direction
10. 1/R₂
11. inverse
12. no
13. constant height above sea lel
14. yes; electric fieldis perpindicular to the surface
15. 10 000
16. ionizes the air, electrons accelerate
17. ability to do work when electrons flow; volts
18. Ep=qV
19. charge in chemical form
20. charge, energy electrical field, foce, volt/potential difference

We got another work sheet. Here are the answers:
1. loss PE = gain KE
2. force; distance; W=Fd; increases; equal
3. potential; voltage
4. 1V
5. 12J
6. 5000 V
7. 5000V
8. 5000V
9. .005J
10. charge

We did a lab and hand that in ASAP

We also got more handouts and a worksheet for long weeked homework!

next scribe is...caroline

HEY HEY HEY! Well for those who missed today's class we received a couple worksheets, which pretty much is about ELECTRIC FIELDS. We also talked about the differences between electric force and electric field, also the differences between gravitational field and gravitational force. Also a handout of Electric Potential. That's what we pretty much did in class today. SO FOR THE NEXT SCRIBE........I PICK........



LINDSAY

Heeey guys!!! It is Linger here, and I am your scribe for today and yesterday's class. Anyway, let's begin!!!

Yesterday was the last day of presentations for our projects on Space Exploration. We had Mark present his but due to technical difficulties, others could not present theirs. If you haven't already presented yours, all you need is a group of 5 volunteers to watch your presentation during a lunch hour... it's better late than never! We also had the worksheet called ELECTRICAL FORCES. And that brought us to the end of class. Homework was to finish number five.

In today's class, we corrected the worksheet and Ms. Kozoriz explained how to do number five. We also got a booklet about Coulomb's Law. The first page was based on One Dimension. The second page was about Two Dimensions using equilateral triangles. The third page was about Two Dimensions using squares with indvidual forces and last page was Two Dimensions using squares and adding the forces. The booklet was pretty straightforward. It tells you what to do step by step in certain situations. Remember to convert the measurements to meters if it is given in centimeters. Also, remember to square the value in the denominator!

After discussing this booklet, we were to read pages 415-420 in the red textbooks. For Practice, do problems 1-5 on page 420. Questions 15 and 16 on page 423 are to be handed in for marks and in order to write the unit test.

Well that is it for me. For further help or explanations, make this blog your friend and scroll down to the slides that was posted for today and/or yesterday's class. Anyway, the next scribe is none other than....

BAAAALEEEE!!!!

Coulomb's Law Problems

Hello I'm Albert, the scribe for this weekend.

What we did last friday was....what was it?

oh!some of my classmates including me did the bus ridership.
After we went back, we continue to watch the presentations by our classmates.

The first group was about disasters that happened to astronauts here and in space.
The second group is about the tools that scientists used to explore space.

and that's it..

Next scribe is jillaine!

Project Presentations/Start of Electric Fields

For today's class, students presented their Astronomy projects. And tomorrow, there will be 6 (assuming) other students presenting their projects as well. After the presentations, we started on Electric Fields, and were handed 2 sheets. Tomorrow's scribe will be Albert.

Gravitational and Electric Fields

TODAY was the test of the "Exploration of Space and Low Earth Orbit". It was just a one yellow page and that is worth 42 marks. We used the foolscap paper to answer the test. There are only 13 questions, and worth either 1, 2, 3, 4 or 5 mark each! WEll thats all the information i can give out today just because there are a few students who didnt do the test! Good luck to those who didnt do it yet!


The nex SCRIBE is......VAN

Exploration of Space/Low Earth Orbit Review

Scribe Post

Ok, today we reviewed for the test tomorrow, If you skipped or are in Cal. you should talk to someone that was in class, because the test will become more clearer with the notes. Also we started our presentations on the Space stuff. (I went first, heh bonus marks...................................). And thats it, and remember Ms. K, BONUS MARKS!! :D



Next Scribe is: charlotte

Hello, I'm the blogoer for today, we went over worksheets in class.
We went over the Concept and Devlopment Pratice page 14-1

We had weekend homework on
Chapter 8,
Practice problems
P.166
Q: 5,6,7,8 and

Problems on
P.173
Q: 20,21,22,23

Also went over some formulas in class.... and thats about all we did~! okayyy
~~~~


next is ('0') JILLLLLLLLAINE

Satellite Problems

MAY 1ST & 2ND, 2007

So today in Physics we went over a few worksheets.
See the Slidehare below for the answers.

DO 31-33!!!!

NEXT WEDNESDAY IS THE TEST! (EXCEPT FOR CALCULUS CHILDREN)
PRESENTATIONS ARE ON TUESDAY AND THURSDAY.
***BONUS POINTS FOR PEOPLE WHO PRESENT ON TIME.

May 3 -
We watched a video on satellite motion. Ask Ms. K for the worksheet you missed.

NEXT BLOGGER IS ...JOHNNY!

Escape Velocity Problems

Scribe post: may 1, 07

For Today's class:
- Circular Motion, Work and Energy Test was handed back
- Chapter Eight lab was handed back


After everyone received their work, Ms. K went over the answers for the test.

Here is the demonstration presented to the class:

Energy is used to move the rocket away from the earth. When the rocket moves an infinite distance away from the earth, the gravitational potential energy that the rocket possesses is 0.












Newtons Law of Universal Gravitation:
F_g = (GM₁M₂)/R²

F is proportional to R²

vector quantity

measured in Newtons

Gravitational potential energy:
E_gpe = - (GM₁M₂)/R

E is proportional to 1/R

scalar quantity

measured in joules

After this, we did a transparency sheet, which we handed in. For the rest of the class a Gravitational fields worksheet was handed out. There were also questions on page 273 of the DUCK book... QUaCK QUaccKK!!


NExt scribe is the person who was supposed to be scribe today. =\

What we did this Thursday

I can't really remember what we did on Thursday so this blog will be kind of short.

We had a sub on Thursday, it was Mr.Newman. On this day we went over
the sheets that Ms K had given us the day before. These sheets where about defining
gravitational potential energy. It's basically about how much energy rockets have on
the earth and how much they have after they have left the earth and what is the escape
speed they need to have, i think it's around 11.2 km/s.

April30

Hi, my name is Jamie and I’m the scribe for today. (Sorry for late posting; computer wouldn’t work)

Today in class, Ms K talked about the booklet on Gravitational Potential Energy/Well, Escape Velocity, Total Energy and Binding Energy.
Now, I will just summarize what we have covered up today; including the work sheet on Gravitational Energy.

Gravitational Potential Energy

According to Newton’s Law of Universal Gravitation, force of gravitational attraction between 2 masses (m₁ and m₂), at any separation distance (R), is given by an equation:

F=Gm₁m₂/R² (where F is a vector)

To increase the separation of 2 masses from R₁ to R₂ requires work to overcome the force of attraction (ex. stretching a spring) which increases the gravitational potential energy. After remembering the relationship between gravitational force and separation (shown below as a graph), the resultant equation for the change in potential energy is:

∆E_gpe = (-Gm₁m₂/R₂) – (-Gm₁m₂/R₁)
^Potential Energy at R₂ ^ Potential Energy at R₁
The 1st term depends on R₂ and the 2nd term on R₁ (each term is an expression for the gravitational potential energy or E_gpe at that separation)


At any separation distance R, E_gpe, between m₁ and m₂, the equation is:

E_gpe = -Gm₁m₂/R (where E_gpe is a scalar; G is constant; R is distance between 2 masses)
Each side of the equation is proportional.


Gravitational Potential Well

* E_gpe = -Gm₁m₂/R always produces negative values.
* As R increases (masses get farther apart), E_gpe increases by becoming less negative.
* As R approaches infinity, PE approaches zero. Zero value of E_gpe between 2 masses occurs when they are infinity apart.

The two objects that have force of attraction between them resulting negative E_gpe is called a Potential Well.

Example:



Pretend the m₁ is the earth and m₂ is the rocket. For the diagram above, R₁ represents the earth’s radius. If rocket is at rest on earth, then there is no KE on the rocket, only E_gpe which is equal to – Gm₁m₂/R₁.

Total energy of rocket (E total), where is just the E_gpe , is the sum of E_gpe and KE:

E total = E_gpe + KE

Assuming that the rocket rises above Earth’s surface to a height of R₂ where it has less E_gpe and some KE. The E total of rocket remains the same constant value.

E total = KE + E_gpe = KE + (-Gm₁m₂/R₂)


Escape Velocity

We must know the earth’s Potential Well when trying to calculate minimum velocity (Escape Velocity) the rocket must have to escape. Rocket’s initial KE must exceed depth of the potential well at earth’s surface, making total energy positive. Meaning, the rocket must reach an infinite distance where E_gpe = 0 before coming to rest.

(USING THE RECENT EXAMPLE…) At Earth’s surface: E total = - Gm_em_r/R_e (where “e” stands for earth and “r” for rocket”)

Energy is then change to KE if the rocket: KEr = ½ m_rv_r²

* ½ m_rv_r² = - Gm_em_r/R_e

Therefore, V_r = √2Gm_e/R_e

A rocket launched from earth w/ a velocity greater than 1.12 x 10⁴ m/s will move away from earth (losing KE and gaining E_gpe ).
* Since KE is greater than depth of its E_gpe , its total energy always remains positive.


Total Energy and Binding Energy

For rocket to escape from earth’s potential well, its KE must exceed the E_gpe and if this doesn’t happen, it is said to be bound to earth.
Binding Energy is amount of additional KE it needs to escape.

For rocket at rest on earth’s surface, binding energy is identical in magnitude to E_gpe at earth’s surface (rocket’s not moving).

E total = KE + E_gpe = 0 + (- Gm_em_r/Re) = - Gm_em_r/Re
E binding = Gm_em_r/Re

* If rocket is in orbit at any radius Ro in potential well of earth, then the centripetal force that keeps the rocket is the circular orbit is provided by force if gravitational attraction between earth and rocket.

If rocket has mass m_r and an orbital velocity of v_r:

Fc = Fg OR m_rv_r²/Ro = Gm_em_r/Ro²

Total energy is:

E total = KE + E_gpe = 1/2 m_rv_r² + (- Gm_em_r/Ro) = ½ Gm_em_r/Ro +
- Gm_em_r/Ro = ½ Gm_em_r/Ro = ½ E_gpe

* Total energy of satellite in a circular orbit at any radius of orbit Ro is negative and equal to ½ the value of E_gpe at this radius.
* Satellite is bound to earth and its binding energy is:

E binding = ½ Gm_em_r/Ro







To be continued……

April 27, 2007

We started the class off by going over questions 1-5 that was for homework. The answers are on the previous blog that Ms K posted up....

BTW: question #5 is for bonus marks. so if you want the extra marks i think you should do it.

After our fellow students helped the class with the homework questions there was a sheet handed out with the "Inverse Square Law" lyrics on it. Ms K played the song for us which was .... very interesting :/

K well anyways. we got another sheet about Inverse-Square Law (the one with the diagrams [paint spray & hand])

if you didn't get the answers to this... here they are...

question 1:
1 area unit = 1 mm thick
4 area units = 1/4 mm thick
9 area units = 1/9 mm thick
16 area units = 1/16 mm thick

question 2:
5 m from source? 25
10 m from source? 100


Ms K then handed out another sheet which covered "Gravitational Interactions"
This sheet will help you understand how to use the equation
F=G(m₁m₂/d²)

(sorry i dont know how to do subscripts or even superscripts or whatever... sorry)

answers:
1) if both masses are doubled, what happens to the force?
Fnew = G(2m₁2m₂/ d²)

2)If the masses are not changed, but the distance of separation is reduced to 1/2 the original distance, what happens to the force?
F = G(m₁m₂/ ½d²)

3)If the masses are not changed, but the distance of separation is reduced to ¼ the original distance, what happens to the force?
F = G(m₁m₂/ ½d)²> = 1/(1/16) = 16F


4)If both masses are doubled, and the distance of separation is doubled, show what happens to the force.
F = G(2m₂2m₂/ 2d²) = 4/4 = 1F

5)If on of the masses is doubled, the other remains unchanged, and the distance of separation is tripled, show what happens to the force.
F = G(2m₁m₂/ 3d²) = 2/9 = 2/9F

6)Consider a pair of binary stars that pull on each other with a certain force. Would the force be larger or smaller if the mass of each star were three times as great and if their distance apart were three times as far? Show what the new force will be compared to the first one.
F = G(3m₁3m₂/ 3d²) = 9/9 = 1F

this sheet is more about understanding how to use the equation and how to interpret what's being asked and form it into an equation...





okay well there's another sheet given... "Universal Law of Gravitation"

We just worked on this worksheet until class ended so if you did this then good job...your on task and ready for more work :) that's the end of my scribe and yes i guess i have to choose the next one which is....lemme see ?!?!? ...gear321

Kepler's Problems

chapter 8 study guide

what we did yesterday in physics class was:
- we checked out the questions from the book that she assigned on monday.
- completed the first paragraph on study guide 8.1 (Kepler's law of planetary motion).
- we answered the motion in the heavens and on earth question.
- we did some examples to understand how kepler's last law works.
- she gave us some questions to do, to practice kepler's law.
that's it i think. hahahahaha
sorry Ms. K. i forgot to do it yesterday.
Boot5 to scribe for Wednesday.

Kepler's 3rd Law Problems

Scribe

Hey it's Anh for the physics scribe today...so what did we do today?
Well we started off the class with a 20 minute video, which was of course being disruptive by Jennie..haha just kidding. The video was about Johannes Kepler's life and his discoveries. It was sort of like an autobiography.
During the movie we were required to fill out a sheet with 21 questions which are listed below with the answers:

KEPLER'S THREE LAWS VIDEOTAPE
1. What planetary model did Johannes Kepler believe in?
The Copernican model
2. Which planet's orbit did Kepler analyze?
Mars
3. How far off from a circle was the orbit of Mars?
8 minutes of arc or 1/4 of apparent width of the moon.
4. What type of curve can explain the orbit of Mars?
An ellipse
5. In an ellipse, is the total distance from 1 pin to the string and then to the other pin, a constant?
Yes
6. The name given to a single point in an ellipse is the ______.
Focus
7. Focus is the Latin word for ______.
Fireplace
8. How would you describe Kepler's childhood?
Poverty and illness
9. What journey did Kepler undertake in 1600 and for what purpose?
Tycho Brahe
10. What was the main interest of Tycho Brahe?
Astronomy
11. How did Kepler obtain the careful observations that Brahe made during his lifetime?
He stole them
12. Was the Copernican model of the universe easy to justify scientifically?
No
13. What were some of the problems that faced Kepler in discovering the secrets of the sky?
Movement, earth spins on an axis while revolving around the sun.
14. How many pages of calculations did Kepler have?
Over 900 pages
15. What does "in opposition" mean according to the positions of Mars, Earth, and sun?
Mars is seen at the same position, if seen from earth or sun.
16. Can any circle viewed obliquely be termed an ellipse?
Yes
17. In ancient history, which group of people studied conic sections?
The Greek
18. Is a parabola a popular shape in our world today?
Yes
19. In your own words, describe the term eccentricity?
How flat an ellipse is
20. State Kepler's 3 laws.
I Each planet moves as an ellipse with the sun at one focus.
II A line from the sun to each planet sweeps out equal area in equal time.
III T² is proportional to R³
21. How did Kepler earn money in later life?
Made astronomical charts

So after we went over the video sheet answers we did a lab applying Kepler's ideas which is in the textbook, page 158.

And that is where the class and this scribe post ends. Next scribe is Nivram?

bye bye bye bye bye bye bye bye bye bye bye bye

NEW UNIT, Motion of the Earth and Heavens ohhhhhhh~~~! ^___^

Hi~! ---->

In physics class okay we all had received worksheets and we started a new unit. Here are a list of worksheets.

Chapter 8 Study Guide:
8.1 Motion in the Heavens on Earth
8.2 Using the Law of Universal Gravitation
[ Page 156-165 ]

A booklet:
8 Study Guide booklet

A paperthingy:
Why Explore Space?

And finally the last handout:
Grade 12 Physics Project: Exploration of Space

hrmss... lets see @_@ yeah.... and that was all we did on Fridays.

The next blogging is.....

Circular Motion/Work and Energy Review

Conservation of Energy

In today's class, we went over the questions that was for homework from the book on p. 237 PROBLEMS #s 1, 2, 6, 8, 13, 14, & 21... If you need the answers, I'll just post them maybe tomorrow. After doing the questions, we watched a video about "Conservation of Energy".

Here are the answers for the questions in the sheet that Ms. K. gave us today...

1. What quantities are conserved?
- energy,momentum,angular momentum

2. If energy is conserved, how are things started and stopped?
- Things are started and stopped by work. (the transfer of energy from one type to another)

3. If energy is conserved, why do muscles get tired?
- Muscles get tired because of work.

4. If energy is conserved, why do weights fall?
- Weights fall because of the work.

5. What formula is used to calculate work?
- The formula used to calculate work is W = mgh

6. What is the role of work?
- The role of work is to transfer energy from one place to another.

7. What symbols are used for potential energy?
- The symbols used for potential energy are u or PE.

8. How is potential energy calculated?
- Potential energy is calculated by using the formula u = mgh

9. Is potential Energy by itself conserved?
- No.

10. Which scientist investigated the concept of energy conservation?
- Galileo Galilei

11. What is the formula for kinetic energy?
- The formula for kinetic energy is K = ½ mv²

12. How are kinetic energy and potential energy related?
- E = u + k = constant (Although the energy changed from kinetic to potential and back again, the total amount of energy stays constant.)

13. Who formally stated the law of conservation of energy?
- James Joule

14. Briefly describe this experiment.
- James was calculating how much mechanical energy can be converted to heat.

15. State the two mechanical forms of energy.
- Potential energy and Kinetic Energy

16. Can mechanical energy be tranformed to heat?
- Yes.

17. Is heat a form of energy or is energy a form of heat?
- Heat is a form of energy.


That will be all for today!


The next scribe will be...

sjdhsd

Physics.........................

We did a lab about Hooke's Law today. We used a spring in a stand and we attached different kinds of masses and we measured and recorded the extension of the spring. Using the data we gathered, we have to do a graph about the relationship of the force and the extension of the spring, then using those information we can solve the problems in the worksheet. Basically, all we did today is the Hooke's Law lab........That's It!!!!........................PEACE!!

Next Scribe is...........................



Kristel

Friday the 13th's Physics Class

Hello guys! As you all remember, we went over some exercises and notes in our class. We did less work because Ms. K was not around but a substitute named Ms. McQueen filled in. As a comment for our substitute, she made our friday's class fulfilled because she covered all of the works Ms. K asked her to do. Anyway, this is the list of all the things we did.

1. Go over 8.3
2. Overhead notes
3. Hand-out sheets- Force and spring and Hooke's law
4. On problems p.237-239
nos. 1, 2, 6, 8, 9, 13, 14, 20, 21

We went over the answers for the concept-development 8.3 sheet. (Click the images to see the content larger)

Then Ms. McQueen discussed the overhead notes. The notes was about the derivation of the equation.



Afterwards, she gave us the hand-outs entitled "Force and the Spring". A little explanation of the sheets was discussed to us. Thereafter, we were told to answer the exercises in the book.

That's all what we did last friday and God bless us all in Physics.

The next scribe is Ian...............

What we did on physics?

ruschev


hi!...hello!.....how are you?....doing great!....so what did you do on Physics today? oh we corrected the review sheets, Miss K gave us last Monday, oh really? yeah! most of the corrections are on the smart board so just go visit Miss K's post and get the right answers. WOW that is so cool! what did you guys do next? she gave us a work sheet before the class is over. oh really? is it for marks? I don't know so you better do it! WAAAAAAHHHH! okei dokie bye! see you! au revoir!

DAPHNE I CHOOSE YOU!!!!!!! WAAAAAH!

Answers to Work Questions

PHYSICS LAB : Down the hill

Hi. everybody!!!
I hope everyone is in good spirit this spirit week!!!
I'm Ricardo your scribe for today!!


What we did in our class today is a lab activity. The lab is all about potential and kinetic energy. The lab activity can be found in the book at page 225.

That's all we do for the whole period. Don't forget to hand-in your lab tommorrow.

To know more about Kinetic and Potential energy, visit this site. click me

The next scribe will be Ruschev...!!!!

That's a lot of "Work!"

Hello everyone this is Manny your scribe for the day.

So we started todays physics class going over the Force Centripetal lab we did before the weekend.

Then we looked over the page 56-57 of the chapter 10 study guide. The answers to those sheets are here below.


Afterwards, those who didn't do the lab on thursday, like me... did. Meanwhile, the others worked on new handed out worksheets.

And that was pretty much everything that happened. Next scribe will be ricardo, and that will be for Wednesday's class as there is an event tomorrow.

Remember to complete the textbook questions mentioned in Mark's scribe post below as we are going to go over it next class.

What We Did In Class =)

This is Mark Bale your next scribe =)

Well we basically just did a quick browse on Work: Defenition and Work Done by a Variable force.

We also went over the study guide, so for those who don't have the words find a classmate who has them.

Half of the class we did a lab which is in your text books on page 204

So your homework for the weekend is to:
-complete page 56 & 57 in your Chapter 10 study guide
-do review concepts problems 1-5 on page 212
-do app. concept problems 1-6 on page 212 - 213

That's all we basically did. For the next scribe I pick Manny to do the next scribe.

Scribe Post

This is Lindsay, the scribe person for today.

In class, we watched a video that showed us examples of circular motion.

One example would be the Merry-go-Round. It has a fictitious Coriolis force. I think that's what the video told us, I'm not quite sure, sorry.

Another example was the roller coaster. The liquid in the container (the accelerometer)changed levels when it went around the loop.

The last example we saw was the carnival rotor ride. There was an outward inertial force. The people in the ride were in a state of equilibrium because of the artificial gravity. They were being pushed against the wall, away from the centre.

After the video we corrected the questions 13-17 on pages 152 and 153.

Ms. K showed us a free body diagram on the smartboard. The coin was traveling in a circular path and it experienced a gravitational force, normal force, and force of friction.

We're done with circular motion! (well not until the test...but you know what I mean)

Lastly, we received handouts about Work and Energy!

Do your homework and I hope you guys handed in your labs.

I choose you, bale-0ut! for the next scribe.

circular motion....

wow i can't believe it...Ms. K wants me to be the scribe today.. well uhhmmm i will start with the first thing that we did a while ago... we answer the exercise that she gave us before we had our spring break. Its all about circular motion and the first page was about centrepetal acceleration...just want to remind all of you guys the formulas on this topic..

Centripetal Acceleration:

1. average velocity- v=2∏R/T

2. centripetal acceleration- Ac=4∏²R/T²

Centripetal force:

1. centripetal force- Fc=ma

After we checked our excercise sheet Ms. K gave us a hand out about Centripetal and Centrifugal Forces..and if you have read that sheet,you will see two examples of these force,one example is the spinning tub in the washing machine and the other one is the automobile that round a corner,but the best example for me is the spinning tub in the washing machine,well if you read it you'll understand this topic better...

and that's it for now..i can't remember some stuff we did a while ago=)

*richard don't want to email Ms. K because he don't want to be the next scribe*=>

uhhmmm.. next scribe would be "Lindsay"

The 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.

lindsay forgHa_baybhie baLe-Out jennie_s linger

Jamie daphne Manny gear321 ricardo charlotte

J Allen Kristel Ian...NyP vehcsur Boot5

nivram sjdhsd Mark13 Anh albert M.

jillaine

Uniform Circular Motion

General information about circular motion
http://en.wikipedia.org/wiki/Uniform_circular_motion

Referenced from http://www.glenbrook.k12.il.us/gbssci/Phys/mmedia/circmot/cf.html