We have read that when an object that has some force for motion decreases due to frictional force, but in space frictional force is not there, so the object will move is the same speed. So if a planet gains extra gravitational force when it is nearer to the sun then it must become a cycle and the speed must keep increasing whenever it comes nearer to the sun and then the speed must be constant for the other time. Why is it not happening??? Plz explain...
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Changing orbits and changing speed
Long time reader, Fran, asked for a request and I can’t turn it down. What happens when you have a spacecraft that wants to change orbital distances. Do you need to speed up or slow down? Let’s begin. So, I have some spacecraft orbiting a planet – say Earth in a perfectly circular orbit. What […]
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Long time reader, Fran, asked for a request and I can't turn it down. What happens when you have a spacecraft that wants to change orbital distances. Do you need to speed up or slow down? Let's begin.
So, I have some spacecraft orbiting a planet - say Earth in a perfectly circular orbit. What must be true? Well, I have done this one before, so let me cut to the chase. The space craft only has one force on it, the gravitational force. Also, it is accelerating because it is moving in a circle. Here is a diagram.