V
verizen":31vmkdr2 said:Hello, I am having trouble with a question in my textbook and was wondering if anyone could help me out with it. Here's the following question, as followed...
I want you to Calculate the angle subtended on the Celestial sphere by the separation of Venus and the Sun when the Earth and Venus are separated by about 90 degrees from an observation point on the Sun. Assume circular orbits for Venus and the Earth show your work.
I don't understand how to calculate or the which method to use.
I came up with this parallax, it's not exactly accurate but hopefully you have a better idea then what I've generated..
o<Venus

O<Sun  90 O<earth
verizen":4i1jp2j3 said:o<Venus
 \
O<Sun  90 O<earth
aphh":feah1vkn said:verizen":feah1vkn said:o<Venus
 \
O<Sun  90 O<earth
If that's your situation, why not simply use the distances of Earth and Venus from the Sun, and calculate the angle using tangent like this,
tangent Sun  Venus = (distance Sun  Venus) / (distance Sun  Earth) ?
So if the distances were
Earth = 1 AU
Venus = 0.72 AU
0.72 / 1.00 = 0.72, take inverted tangent (tan^1), and you'd get 38.8 degrees separation between Venus and the Sun from Earth's perspective (as per your scenario).
Tangent is the trig function that fits your bill, as it is TOA, meaning opposite side of the angle over adjacent side. You need to refresh your basic use of trig functions on right triangle and Pythagora's law, before proceeding.
Yeah about that diagram it was written incorrectly the planet venus is suppose to be aligned with earth and the sun being the observation point...
No your right with your statement, but the way the diagram was displayed is incorrect the earth is supposed to be 90degrees from Venus.origin":wgjkcst9 said:Yeah about that diagram it was written incorrectly the planet venus is suppose to be aligned with earth and the sun being the observation point...
Really? That seems hard to believe, because the angle would be zero, unless I am missing something....