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sunny5679
7th Jun 2006, 14:24
Hi is anybody can solve this
An aircraft flies the following true RL tracks and distance in NM in succession
000 deg. 600 nm 090 deg 800 nm 180 deg.600 nm 270deg 800 nm
and arrives back at its starting place. The latitude of the starting point must be.
85 deg. N / 85 deg S / 5 deg S / 5 deg N

thanks

GusHoneybun
7th Jun 2006, 16:10
5 degree south. the trick is to make sure that the flights east and west are on the same relative latitude.

sunny5679
8th Jun 2006, 15:54
thanks for this answer, but i do not understand why it is 5 deg south.because in the question, asking the latitude of the starting point,
and the starting point is 000 deg. i think it should be 5 deg. North .please let me if i am correct.
thanks
sunny

SILENT_BADGER
8th Jun 2006, 18:10
I agree with the Gus feller - if you start off with a track of 000 or 360 then you're going North, and if you are going to have equivalent latitudes for the east/west legs then you need to cross the equator half way through that 600nm leg. So you need to start at 5S.

Cheers,

SB

Keith.Williams.
9th Jun 2006, 07:08
To understand this problem you must take two factors into account:

1. The meridians diverge as you move towards the equator and converge as you move away from it.

2. If you move the same distance north, then south, then east, then west,
your end point will depend upon the relative magnitudes of any convergence or divergence which occur. You will end up at your starting point only if the diveregnce/convergence going north is exactly equal and opposite to the divergence/convergence going south.

This question specifies 600 nm. Each minute of arc on a meridian is one nm, so 600 nm is 10 degrees.

If you are 5 degrees south of the equator and start by going 600 nm (or 10 degrees) north you will get divergence over the first 5 degrees (up to the equator). You will then get the same amount of convergence over the next 5 degrees, as you move away from the equator. So the overall efect of the convergence/divergnce will be zero.

The same will happen during the southerly leg of the journey. So you would end up back where you started.

If you now look at the efects of starting at 85 north or south, you will see that this self-cancelling effect does not occur.

sunny5679
10th Jun 2006, 06:01
thanks for this explaination. now i understand.:)