Calcuate Orbital Speed (without using distance)

In summary, calculating the orbital speed of a planet without using the distance of its path can be done by using other orbital parameters such as orbital period and eccentricity. If the orbit is close to circular, you can find the average orbital speed as a function of the orbital period alone. Further understanding of fundamental concepts may be needed to solve this.
  • #1
ldv1452
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How would I go about calculating the orbital speed of a planet without using the distance of its path. In other words, only using the motion around the plane of ecliptic?

My first thought was using the angle of the path somehow, but I'm a bit stumped here.

Thanks for any input!
 
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  • #2
Assuming "distance of its path" is referring to the semi-major axis of the orbit, a, you can replace a with knowledge of other orbital parameters such as orbital period T and eccentricity e. Assuming further that e is close to zero (orbit is near circular) you can find average orbital speed as a function T alone. To do this you probably need to look for some equations in your textbooks that relate these parameters to each other and combine them, or you could read some of the references that come up when you search for "orbital speed" ... *cough* wikipedia *cough*
 
  • #3
Thanks for taking the time to reply. I think I need a better understanding of some of these fundamental concepts before I can solve this.
 

1. How is orbital speed calculated?

Orbital speed can be calculated by using the formula v = √(GM / r), where v is the orbital speed, G is the gravitational constant, M is the mass of the central body, and r is the distance from the center of the central body to the orbiting object.

2. Can orbital speed be calculated without knowing the distance?

Yes, orbital speed can be calculated without knowing the distance by using the formula v = √(GM / r), where G and M are known constants and r can be assumed to be the radius of the central body (e.g. Earth's radius for objects in low Earth orbit).

3. What units should be used for orbital speed calculation?

The units used for orbital speed calculation can depend on the values used for G, M, and r. Typically, G is measured in m^3/(kg*s^2), M is measured in kilograms, and r is measured in meters. Therefore, orbital speed is often calculated in meters per second (m/s).

4. Can the orbital speed change over time?

Yes, the orbital speed can change over time due to various factors such as changes in distance from the central body, gravitational pull from other objects, and atmospheric drag. However, in a stable orbit, the orbital speed will remain constant.

5. How does orbital speed affect the orbit of an object?

Orbital speed affects the orbit of an object by determining the shape and size of the orbit. A higher orbital speed will result in a larger orbit, while a lower orbital speed will result in a smaller orbit. Additionally, changes in orbital speed can cause an object to move into a different type of orbit (e.g. from a circular to an elliptical orbit).

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