Scribe^2

Well, sorry class and sorry Ms. K for not posting yesterday, I rarely have access to the computer so it's difficult to scribe or sometimes to check the blog at all. Well, on with the scribe for monday, October 29, 2007.

Class began as Ms. K was setting up a movie on the television screened parked somewhat diagonal from the front desk. She also notified the class that the labs were to be handed in by the end of class, and to make sure that we all hand our labs in successfully. We then diverted our attention back towards the television set as Ms. K handed out a sheet containing several questions pertaining to the imminent movie. These questions were as follows:

1. Can an object move with constant sped and accelerate at the same time?
2. What is special about a vector originating from the center of a circle to a point on the circle?
3. State the two ways of finding the position of a point on a circle.
4. Briefly describe the Copernican universe.
5. Who revealed how the Copernican system worked?
6. Using the circle below, draw the acceleration and force vectors. Are both vectors in the same direction?
7. How is acceleration defined?
8. What is speed?
9. Can a body accelerate if speed is constant?
10. What does the rate of change of a vector mean?
11. Give three ways a vector can change.
12. Using the circles below, draw the radius and velocity vectors on circle 1, and then draw the velocity and acceleration vectors on circle 2. What is the relationship between both pairs?
13. What equation gives the relationship between acceleration, velocity, and radius?
14. If you superimpose vectors from circle 2 on the vectors from circle 1, what is the direction of the acceleration vector?
15. Is a force needed to accelerate a body in circular motion? What is the name of this force? What direction does it take?
16. If the moon is in orbit around the earth, what force is causing the moon to maintain its uniform circular motion? State the mathematical equation for this constant speed.

And then we continued on with the movie!

The movie was extremely fast paced in terms of the conveyed knowledge within each segment. When watching the movie many people in the class scrambled to assemble their answers to the questions she handed to us, and ipso facto Ms. K gave us an excess of 10 minutes to confer our results amongst our peers prior to reviewing the answers. The answers are as follows:

1. An object can in fact be constant in speed and accelerate simultaneously.
2. A vector inscribed within a circle drawn from the center to any point along the circle will always be equal in length as the point on the circle is altered. This is due to the fact that such vectors would be the radius of the circle.
3. They can be found by either:
- Cartesian co-ordinates (x,y)
- It's distance from the center of the cirlce and the angle from which this measurement is taken relative to the horizontal. (In other words, the position can be found by using trigonometry)
4. The coperinican theorem of planetary revolution consisted of the planets revolving the sun in a nearly uniform circular motion (each planet's moons, particularly Earth's, are described to have the same motion).
5. Nicolaus Copernicus' theory of planetary revolution was further explained by Sir Isaac Newton.
6.

The vectors are both directed towards the center of the circle ergo they share the same direction.
7. Acceleration is simply described as the change in speed or velocity.
8. Speed is the length or the magnitude of the velocity vector.
9. A body can indeed accelerate if it's speed is constant (as in the case of circular motion).
10. The rate of change of a vector indicates how fast a vector is changing.
11. Three ways that a vector can be altered are as follows:
- The size or magnitude of the vector.
- The direction of the vector.
- Both of the aforementioned methods.
12. The relationship between both pairs is that they are perpendicular to their respective vector quantities.
13. a = v² / R
14. The acceleration vector would be opposite the radius ,or rather towards the center of the circle.
15. Yes there is a force accompanying bodies in circular motion, i.e. Centripetal force, and this force acts towards the center of the circle.
16. The force responsible for such phenomena is known as gravity. The mathematical equation interrelating circular motion and gravity (though we are not required to know this formula quite yet) is given by:
V = √(Gm_e/R)

Once we concluded this portion of the class, Ms. K then showed some more short clips that pertained to circular motion, the first of which relied on a professor indicating that the magnitude of displacement is the radius of the circle, and a velocty vector consistent in magnitude is perpendicular to the displacement vector. He then projected the fact that acceleration is also constant in magnitude, but is directed towards the center of the circle. Then we watched some cool videos of children that were playing on a merry-go-round, displaying some of the indefinitely entertaining properties of circular motion. Once the movie sessions were done with for the class, Ms. K let us work amongst our peers on whatever we had to finish.

Some questions that we were given time to work on if not already finished over the weekend were the questions found on Centripetal Acceleration and Centripetal Force. And that concluded our class for monday. The scribe has already been determined for today, and that scribe is:
AICHELLE

dixi