TGIF

Wow I thought the week would NEVER finish. But it's Friday now! :D and I almost forgot that I was scribe. ^_^"

So in today's class we went over a lot of problems/worksheets. For most of the worksheets Ms. K wrote the answers on the smartboard and posted it up below this scribe post.

We also went over the green textbook questions on the white board. I didn't get all the answers down.. I apologize.
But for number 6, 7 and 13 you use the F=Gm1m2/R² formula
Number 18 you use m=4π²R³/GT²
Answers that I do have;
#7: 4.17 x 10²³ N
#13: m1 = 0.37kg, m2 = 0.74 kg
#18: 5.65 x 10^{26 kg}

She then assigned more problems for us to do from the same page (172), numbers 17, 20, 21, 22 and 27 in the green textbook.

We then watched Febi and Elizabeth's Hubble Telescope presentation, nice.
And that was the end of class!
Next scribe is aebe :)

I noticed that no one has blogged for a long time ... A week, actually? So I will blog for today's class because I can't remember that far back... Yesterday, however, the class was taken up by the spirit week event. Yay school spirit~

Anyway... In class, we went over the Chapter 7 Study Guide, Periodic Motion; CIRCULAR MOTION.
Answers: constant, changing, changing, constant, perpendicular, tangent, instantaneous velocity, length, direction, radius, centre, centripetal, directly, inversely, second, force, centripetal force, straight, and tangent.

That was the only paragraph we went over.

We then looked at the free body diagrams worksheet, you may refer to the "Free Body Diagrams-Circular Motion" slide uploaded by Ms K.

After that she wrote us an assignment to do from the "duck book" textbook.
Which was to read p. 202-206, and do problems 1-5 on page 206.
She also wrote - Note: derivation of formula on p.205

If you didn't bring a textbook home, here's one question you can try:
The outer edge of a 120-mm-diameter CD-ROM experiences an acceleration of 1.6 m/s². What is the speed of the CD-ROM?

Reading the textbook would really help, because it stated that
V = d/t (velocity equals distance over time)
can be modified to
V = c/t (velocity equals circumference over time).
And since C = 2πr (circumference equals two times pi times radius), therefore,
V = 2πr/t

So that's all we did in class. I believe our catapult projectile motion project has been pushed to Thursday because of the talent show tomorrow. Yay~

Next scribe is sonson. :)

Scribe Post

Hello!

To start things off in today's class Ms K handed out "Acceleration assignment", which is due on MONDAY.
She then after got a few of us to "warm up" with visual examples of;

• Two moving "cars"(students) and one "cop". Car A moving at 4 mph and Car B at 10mph. Ms K used problem scenarios for us to determine the speed of an object, under different reference frames.
  Ex) Car A and Car B are moving in opposite directions.
  A cop car is sitting perpendicularly to both of the cars, what speed does the cop read for Car B?
  What is the speed of Car B in reference to Car A?
  

• She then used a "current" that was 3 mph, and then a "swimmer" at 4 mph (I'm not exactly sure if those were the mph numbers, probably not :P) And again asked us relating questions.

By observing people act out the possible moving velocity problems enables us to really think and understand the concept a lot better than just reading and viewing pictures in the textbook.
And for the rest of the class we worked on the textbook questions from the day before and got two more worksheets, which from what I believe we will be going over tomorrow.

NEXT SCRIBE IS: NT*
have fun:)
OH ~ and Happy Chinese New Year! Wish you all much luck and success in the future... especially in physics ;)