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:
∆Egpe = (-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 Egpe at that separation)
At any separation distance R, Egpe, between m1 and m2, the equation is:
Egpe = -Gm1m2/R (where Egpe is a scalar; G is constant; R is distance between 2 masses)
Each side of the equation is proportional.
Gravitational Potential Well
* Egpe = -Gm1m2/R always produces negative values.
* As R increases (masses get farther apart), Egpe increases by becoming less negative.
* As R approaches infinity, PE approaches zero. Zero value of Egpe between 2 masses occurs when they are infinity apart.
The two objects that have force of attraction between them resulting negative Egpe 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 Egpe which is equal to – Gm1m2/R1.
Total energy of rocket (E total), where is just the Egpe , is the sum of Egpe and KE:
E total = Egpe + KE
Assuming that the rocket rises above Earth’s surface to a height of R2 where it has less Egpe and some KE. The E total of rocket remains the same constant value.
E total = KE + Egpe = 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 Egpe = 0 before coming to rest.
(USING THE RECENT EXAMPLE…) At Earth’s surface: E total = - Gmemr/Re (where “e” stands for earth and “r” for rocket”)
Energy is then change to KE if the rocket: KEr = ½ mrvr2
* ½ mrvr2 = - Gmemr/Re
Therefore, Vr = √2Gme/Re
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 Egpe ).
* Since KE is greater than depth of its Egpe , 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 Egpe 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 Egpe at earth’s surface (rocket’s not moving).
E total = KE + Egpe = 0 + (- Gmemr/Re) = - Gmemr/Re
E binding = Gmemr/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 mr and an orbital velocity of vr:
Fc = Fg OR mrvr2/Ro = Gmemr/Ro2
Total energy is:
E total = KE + Egpe = 1/2 mrvr2 + (- Gmemr/Ro) = ½ Gmemr/Ro +
- Gmemr/Ro = ½ Gmemr/Ro = ½ Egpe
* Total energy of satellite in a circular orbit at any radius of orbit Ro is negative and equal to ½ the value of Egpe at this radius.
* Satellite is bound to earth and its binding energy is:
E binding = ½ Gmemr/Ro
To be continued……
Monday, April 30, 2007
Wednesday, April 25, 2007
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
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
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.
- 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.
Tuesday, April 24, 2007
Monday, April 23, 2007
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.
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
Saturday, April 21, 2007
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.....
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.....
Wednesday, April 18, 2007
Tuesday, April 17, 2007
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
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
Monday, April 16, 2007
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
Next Scribe is...........................
Kristel
Saturday, April 14, 2007
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)
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...............
Thursday, April 12, 2007
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!
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!
Wednesday, April 11, 2007
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.
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...!!!!
Monday, April 9, 2007
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.
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.
Friday, April 6, 2007
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.
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.
Wednesday, April 4, 2007
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.
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.
Tuesday, April 3, 2007
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.
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.
Jamie Manny | J Allen Kristel Ian...NyP | nivram sjdhsd Mark13 albert M. | jillaine |
Sunday, April 1, 2007
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
http://en.wikipedia.org/wiki/Uniform_circular_motion
Referenced from http://www.glenbrook.k12.il.us/gbssci/Phys/mmedia/circmot/cf.html
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