GISELLE?? asked:
why must the centre of satellite orbit coincide with the centre of the earth?
pls provide detailed answers
much appreciate <3
2 Responses to “satellite?”
This is not the case. In fact, if the satellite’s orbit is elliptical, the center of the ellipse most definitely does NOT coincide with the center of the earth.
However, it is true that the plane of the orbit does always _contain_ the earth’s center–perhaps that is what you were thinking of.
The reason is that the force vector (the pull that the satellite feels) is always directed toward the earth’s center. This means (according to Newton’s laws) that the satellite’s path must bend towards the earth’s center too. This continual bending towards the center results in an elliptical path that contains the center. (That’s as well as I can explain it without being mathematical.)
The Earth is approximately a sphere, therefore its centre of mass is in the centre of the Earth.
Newton’s equations defining the force of gravity between 2 objects, define the distance between the objects as the distance between the centre of mass of the 2 objects.
Therefore to calculate the force that keeps a satellite in orbit (gravity) you need to know the distance between the satellite and the centre of the Earth.
I hope this helps, for more information see the website below: