Tuesday April 26 2011

Today, we study the new formula F=Gm1m2/d^2.
And also we go over pg11, 12, 23, 24 in grey booklet.
If you are not finish the Study Guide, so go ahead in pg15, 16

Monday, April 25, 2011

Hi guys! If you miss today's class here are the things that we did.
In the beginning of class Ms. K let us watch videos explaining Kepler's Law of Planetary Motion. If you're unfamiliar with Kepler's three laws, refer to your gray booklet in pages 6&7.

After we watched the videos, we went over Transparency 7-1 in page 21-22. Here are the answers to the questions:
1. gravitational force
2. elliptical
3. at one focus of Earth's elliptical orbit
4. at the point closest to the sun
5. at the point farthest from the sun
6. area(1)=area(2)
7. T(1)=T(2). Since the Earth's velocity varies, the time it takes to sweep out equal areas along its orbit is the same.

Lastly, for tomorrow's class we are to finish pages 15-18.

Hello grade 12's!
During Thursday's class, there were instructions given to us on the board and they were:
1. Finish the orbit lab on page 20 in your grey booklets. (It was due on Thursday at the end of class.)
2. Finish page 22 in the grey booklet.
3. Do problems 1-4 on page 160 in the green textbook. (Answers are at the back of the textbook)
4. Do problems 1-5 on page 172 in the green textbook. HAND IN ON MONDAY!

Here are the questions that were assigned from the textbook:
Questions on page 160:

1. An asteroid revolves around the sun with a mean (average) orbital radius twice that of Earth's. Predict the period of the asteroid in Earth years.
Answer: 2.8 years

2. From Table 8-1, you can calculate that, on the average, Mars is 1.52 times as far from the sun as is Earth. Predict the time required for Mars to circle the sun in Earth days.
Answer: 684 days

3. The moon has a period of 27.3 d and has a mean distance of 3.90 x 10^5 km from the centre of Earth. Find the period of an artificial satellite that is 6.70 x 10^3 km from the centre of Earth.
Answer: 88.5 minutes

4. From the data on the period and radius of revolution of the moon in Practice Problem 3, find the mean distance from Earth's centre to an artificial satellite that has a period of 1.00 d.
Answer: 4.30 x 10^4 km

Questions 1-5 on page 172 (Don't forget that these questions are for marks!)

1. Jupiter is 5.2 times farther than Earth is from the sun. Find Jupiter's orbital period in Earth years.

2. Uranus requires 84 years to circle the sun. Find Uranus' orbital radius as a multiple of Earth's orbital radius.

3.Venus has a period of revolution of 225 Earth days. Find the distance between the sun and Venus, as a multiple of Earth's orbital radius.

4. If a small planet were located 8.0 times as far from the sun as Earth, how many years would it take the planet to orbit the sun?

5. A satellite is placed in an orbit with a radius that is half the radius of the moon's orbit. Find its period in units of the period of the moon.

Enjoy!

Friday, April 15th 2011

Today, we did the lab in Physics class. The lab is in pink booklet page 37.
That's everything we did on Friday.

Wednesday, April 13th 2011

Heyy class for Wednesday's class we went over the answers on Page 24 CHapter 11 Study Guide in the Pink Booklet. The answers are as follows: FORMS OF ENERGY: itself environment kinetic work position shape form DOING WORK TO CHANGE KINETIC ENERGY: mass velocity 1/2mv2 joule increases net change same increases opposite decreases POTENTIAL ENERGY: potential kinetic kinetic potential energy kinetic potential zero kinetic potential inceases potential kinetic mgh (formula) height reference level constant After we went over those answers we went over the answers for the questions on page 237 in the Green Book. After that we did questions 20. b) and c) , 21, 22 and 23 and handed them in. That's everything that we did on Wednesday. Thank you. --janna k
Wei to scribe for Friday's class.

Friday, April 8

In class we looked over the Review from yesterday as well as the the questions on p 213 in the green text book.

Questions 1-5, and 17 -19

1.
W= F*D
W= 80N * 10m
= 800J

2. d= 8m
F = mg
= 150kg * 9.8m/s2
=1470N
W=FD
=1470N*8m
=11760J

3.
w=176J
d= .300m
F=W/D
= 176/.3
= 586.67

m = 586.67/ 9.8
= 59.9kg

4.
W=FD
= (2.25 x 10 3N)(7.50)
= 1.60 x 10 4 J

m=dv
=( 2.00 x10 3 kg/m3)(1.15m3)
m=2.30 x 10 3 kg
Fg=mg = ( 2.3 x 10 3 kg)(9.8m/s2)
= 2.25 x10 3 N
totally Fg = 2.25 x 10 4 N + 2.25 x 103 N
= 2.48 x10 4 N

5.
W=FD
=(3N)(.16m)
= .48J
total .080J

W= 1/2 FD
= 1/2( 4N)(.10m)
=.32J

answers for 17-19

17
a. W= 5527.7J
b. 0 work is done.
c. W= -5527.2J
d. No, doesn't exert the force
e. W = 2352.0N
P = 2.2 x 10 3 watts

18.
a. W= 9 x 10 3 J
b. p .3 x 10 3 W

19.
a. P= 3.44 watts
b. P= 696 watts

lab was also due today.

04/07/11

stair walking lab due on friday april 8 :D

answer problems 1-5,17-20 (p 213-215) on green text book

and do study guide of page 10 of pink booklet (work and energy)