Physics
posted by Thomas .
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

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.
Respond to this Question
Similar Questions

math/physics
Help! I have no idea how to do this. The earth's orbit is nearly circular with a radius R=93x10^6 miles (the eccentricity is e=.017). Find the rate at which the earth's radial vector sweeps out area in units of ft^2/s. What is the … 
physics
the separation of the foci of an ellipse that describes a planet's orbit derermines A eccentricity of the orbit B period of the orbit C size of the orbit D all of the above. I think it is A because the closer the foci, the more circular … 
science
the separation of the foci of an ellipse that describes a planet's orbit derermines A eccentricity of the orbit B period of the orbit C size of the orbit D all of the above. I think it is A because the closer the foci, the more circular … 
Astronomy
The distance between the Earth and Mars when the two panets are at opposition varies greatly because of the large eccentricity of Mar's orbit. The perihelion distance of a planet is given by rmin=a(1e)and the aphelion distance by … 
Precalculus
I don't even how to go about this.... Mars is in an elliptical orbit with the Sun at one focus, as shown in the figure. At its aphelion, Mars is 156 million miles from the Sun. At its perihelion, Mars in only 128 million miles from … 
physics
A comet orbits the Sun with a period of 71.8 yr. (a) Find the semimajor axis of the orbit of the comet in astronomical units (1 AU is equal to the semimajor axis of the Earth's orbit). (b) If the comet is 0.50 AU from the Sun at perihelion, … 
physics
Suppose the Earth's orbit is divided in two by its minor axis as shown in the figure. How much longer in days does the Earth spend in one half than the other? 
Accelerated algebra
Comet C has an elliptical orbit of eccentricity 0.9638 with the sun at one focus. The greatest distance of the comet from the sun is 2940 million miles. Find the least distance between the comet C and the sun. 
Hyperbolas, comic sections
So I have this equation: 36x^2121y^2=49 Which I rearranged to 36x^2/49121y^2/49=1 So I want to go from here and find the eccentricity,foci,asymptotes etc... But I'm getting myself confused. Since my equation is of the form x^2/a^2y^2/b^2=1 … 
Physics
an earth satellite has an elliptical orbit with an eccentricity value, e=0.40 and on orbital period of 10 hours and 54.0 minutes. Find the height above the surface at its closest approach point.