Speed of Satellite at Perigee and Apogee

In summary, the conversation involves solving for the velocity at the apogee in an elliptical orbit using the equations of conservation of angular momentum and energy. The initial attempt to use the equation v=SGRT(GM/r) is questioned and the suggestion to consider the conservation equations is given.
  • #1
bobdream
2
0

Homework Statement


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Homework Equations


g=GMm/r^2
e=c/a
g=v^2/r

The Attempt at a Solution



a) v^2/r=GM/r^2 m<<M
v^2=GM/r
v=SGRT(GM/r)

I don't think this is valid though since the orbit is not circular. I don't know how to alter the equation so it also applies to the elliptical orbit of the problem.

Thanks so much for any help.
 
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  • #2
There are two things that are conserved: angular momentum and energy. Try writing out the equation for the conservation of energy and the equation for the conservation of angular momentum and see if you can solve for the velocity at the apogee.

AM
 

1. What is the speed of a satellite at perigee?

The speed of a satellite at perigee, which is the point in its orbit closest to Earth, depends on its altitude and the gravitational pull of Earth. On average, satellites at perigee have a speed of about 7.8 kilometers per second.

2. How does the speed of a satellite at apogee compare to its speed at perigee?

The speed of a satellite at apogee, which is the point in its orbit farthest from Earth, is slower than its speed at perigee due to the weaker gravitational pull at that distance. On average, the speed of a satellite at apogee is about 1.8 kilometers per second slower than at perigee.

3. Can the speed of a satellite at perigee and apogee be the same?

No, the speed of a satellite at perigee and apogee cannot be the same because the gravitational pull of Earth is stronger at perigee than at apogee, resulting in a faster speed at perigee.

4. How does the speed of a satellite at perigee and apogee affect its orbit?

The speed of a satellite at perigee and apogee determines the shape and size of its orbit. A faster speed at perigee can result in a more elliptical orbit, while a slower speed at apogee can cause the orbit to be more circular.

5. Can the speed of a satellite at perigee and apogee be changed?

Yes, the speed of a satellite at perigee and apogee can be changed by adjusting its altitude and/or using propulsion systems. By increasing or decreasing the altitude, the gravitational pull and thus the speed at perigee and apogee can be altered.

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