## Archive for June 2010

### Sick…

June 14, 2010

To all my classes:

I am at home taking care of sick family, unfortunately this means I can’t be there for you at school.

I expect all of you to contact me if you need to ask a question; I’ve set up a MSN account with messenger for this week if you need to ask a question. The address is:

MrG_at_HPSC@hotmail.com.au

Here are the necessary files and information for each class:

Physics.

Light pages

Light Notes (1,2,3,4)

I expect each student to have read all the notes above, and completed the first two sheets of the “Light Pages” worksheets.

Maths Methods

Good luck on the outcome everyone; ask questions if you need help!

Year 10 Maths

You have all been assigned work to do; please remember that I will be checking your bound references.

See you all in class in seven days!

Mr.G

### When will you realise Copernicus, the world doesn’t revolve around you!

June 1, 2010

Greetings! I hope that you all recall our dear friend Johannes Kepler, astronomer, astrologer, philosopher and all round nice guy.  He was the smart gentleman who brought us three laws of planetary motion.

The first we covered in depth in class – the law of ellipses relating to any object orbiting the sun is orbiting in an elliptical shape (a squished circle), with the sun at one focal point.

Each one of you knows that, no matter what ‘shape’ a triangle is, it will always have 180degrees.  With orbiting planets, the same rule applies, with one point of the traingle always the sun.  Thi is Kepler’s 2nd law – that the orbit of a planet covers the same area in equal amounts of time.  That means, the further away the planet from the sun the slower the orbit.  The link below shows this in action.

And finally, Kepler presented a formula that allows us to calculate average distances from the sun based on orbital periods (and vice versa):  The square of the orbital period is equal to the cute of the average distance to the sun —> T^2=a^3

So now you can go outside, armed with information when you stare up at the night sky. Of course, it helps to have a telescope and I’d recommend that if you’re ever in Sydney to pop into the observatory there – the sky will never look as impressive!

Wishing you all the best of luck in your exams, may the stars shine brightly on you!

http://www.physicsclassroom.com/class/circles/u6l4a.cfm <– this one will help with the understanding of the 2nd law

http://www.youtube.com/watch?v=WTJa8DXlerc (i apologise for the high pitch of this woman’s voice – but seriously – applying songs to your work makes it to remember!)

http://galileoandeinstein.physics.virginia.edu/more_stuff/flashlets/kepler6.htm <– this is a challenge for anyone who wants to get planets to orbit…
and finally…

http://antwrp.gsfc.nasa.gov/apod/astropix.html <– astronomy picture of the day – cos really, what is astronomy if not beautiful!