Astronomy Olympiad: Questions & Discussion

[ritwik06]

Recently I gave my Astronomy Olympiad. There were some questions of descriptive type. If you all don't mind I would like to discuss them here.

 

[russ_watters]

Shoot...

 

[ritwik06]

Shoot...

Here goes the first...

A satellite is 36000 Km away from the equator. What will be the maximum latitude from which the satellite can be viewed.

Well, if it had been a question of geometry, I would have just calculated the angle for cos-1 (6400/42400). My answer would come 81.1...

But what I wrote is about the stability of the satellite. Will the satellite be stable at an altitude of 36000 Kilometres. What do you think??

 

[russ_watters]

It doesn't matter if it is stable or not - it is at 36000km right now.

 

[ritwik06]

It doesn't matter if it is stable or not - it is at 36000km right now.

OK :D It means I was foolish to prove that the satellite was unstable. anyways, here goes the second question:

Light passes through a box containing an arrangement of 4 plane mirrors. If the box is removed, even then light doesn't change its path. Is there more than 1 arrangments possible? What will be the sum of all the angles of incidence and reflection.

I think that more than 1 arrangement is possible. And the sum should always be a constant. Probably 360 degree. Whadda say?

 

[Gokul43201]

I think that more than 1 arrangement is possible. And the sum should always be a constant. Probably 360 degree.

I agree on the first but disagree with the second. I can make any sum from 180* to 720*.

 

[ritwik06]

I agree on the first but disagree with the second. I can make any sum from 180* to 720*.

Oh very well! thanks for that :D The third question.

If a shell of iron just floats inside water. Find the ratio of the outer radius to the inner radius. (Density of iron: 7.87 g/cc)

I have assumed that the shell is spherical. And the the space inside the shell is vacuum. Am I going in the right direction?