Distance from one focus to the other

  • Thread starter Saladsamurai
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In summary, the distance between the foci of Earth's orbit is 5.01*10^9 meters, and the ratio of this distance to the solar radius is 7.2. The solar radius is 6.96*10^8 meters.
  • #1
Saladsamurai
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Am I making this out to be too simple?

I am given: The Sun's center is at one focus of Earth's orbit, how far from this focus is the other focus in meters and in terms of the solar radius?

eccentricity=.0167
semimajor axis=a=1.5*10^11 meters.
solar radius=R=6.96 *10^8 meters

Now if c is the distance from the focus to the center of the ellipse,

e=c/a implies c=ea.

So the foci should just be 2ea meters apart...for which I am getting 5.01^9 meters. Which seems reasonable (I think:uhh:)

Now I am having trouble with the latter part of the problem. I know it is just some sort of ratio. The text says 7.2 solar radii but does not give the answer in meters, so I cannot confirm that either.

Casey
 
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  • #2
AGAIN I AM A JERK! I got it.

Casey
 
  • #3
Well, to find the ratio of the distance between foci to the "solar radius", you will need to know the solar radius! I take it that is the radius of the sun?
 
  • #4
HallsofIvy said:
Well, to find the ratio of the distance between foci to the "solar radius", you will need to know the solar radius! I take it that is the radius of the sun?

Yes. I listed that in post #1. I figured it out, For some reason I was dividing wrong i.e, i had it inverted.

Thanks,
Casey
 

1. What is the distance from one focus to the other in an ellipse?

The distance from one focus to the other in an ellipse is known as the major axis. It is equal to twice the length of the semi-major axis, which is the longest distance from the center of the ellipse to its edge.

2. How is the distance from one focus to the other related to the eccentricity of an ellipse?

The distance from one focus to the other is directly related to the eccentricity of an ellipse. The eccentricity is a measure of how "stretched out" the ellipse is, and it is equal to the distance between the two foci divided by the length of the major axis.

3. Can the distance from one focus to the other be negative?

No, the distance from one focus to the other cannot be negative. It is always a positive value, as it represents a physical distance between two points.

4. How does the distance from one focus to the other affect the shape of an ellipse?

The distance from one focus to the other is a defining factor in the shape of an ellipse. As the distance increases, the ellipse becomes more elongated, while a smaller distance results in a more circular shape.

5. Is the distance from one focus to the other the same for all ellipses?

No, the distance from one focus to the other can vary for different ellipses. It depends on the size and eccentricity of the ellipse, as well as the position of the foci relative to the center of the ellipse.

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