Posted by **Thomas** on Tuesday, April 22, 2008 at 3:39pm.

I have to find the eccentricity of an elliptical orbit with one focus, earth's center, E. I know the formula to find eccentricity is sqrt(1-)(b^2/a^2), but I don't know where to use the radius or if I need it. Do I just need to use the eccentricity formula to find it?

0<E<1

- Physics -
**bobpursley**, Tuesday, April 22, 2008 at 4:00pm
all elliptical orbits have two focus loci. The Center of Earth is NOT a foci of Earths orbit, as the Earth is always moving. Foci do not travel in orbit. Neither is the Sun at a foci, but very near to it. Other planets pull on the Sun, so it moves slightly in time.

Use the eccentricity to find it.

## Answer this Question

## Related Questions

- physics - Suppose the Earth's orbit is divided in two by its minor axis as shown...
- Astronomy - The distance between the Earth and Mars when the two panets are at ...
- physics - the separation of the foci of an ellipse that describes a planet's ...
- science - the separation of the foci of an ellipse that describes a planet's ...
- physics - A comet orbits the Sun with a period of 71.8 yr. (a) Find the ...
- math/physics - Help! I have no idea how to do this. The earth's orbit is nearly ...
- Precalculus - I don't even how to go about this.... Mars is in an elliptical ...
- Physics - A comet orbits the Sun with a period of 72.0 yr. (a) Find the ...
- physics - A comet orbits the Sun with a period of 72.8 yr. (a) Find the ...
- math - Find the distance that the earth travels in seven days in its path around...