How do planets stay in motion?

Question

I know soemthign about Einstiens space time theory but this explains what keeps planets in an orbitital path - the mass of the main planet distorts space time or bends the space time matrix which then makes it difficult for the orbiting planet to get further away from the planet at the centre, this is like having a pole and tying a piece of string to the pole and then at the other end of the piece of string a weight, if we now throw the weight with a substantial force the weight will spin or roate around the pole, if the piece of string is say 1 metre in length then the weight will spain around the pole at a distance of 1 metre from the pole but what happes is the rorating weight begins to slow down and eventually stops and this happens because the engergy used to get the spin going has disperced the rotating weight has run out of energy. The planets rotating seem to not run out of energy so where does the energy come from? Einsteins law explains what keeps it in a certain path just like a peice of string but does not explain from where the energy comes that keeps it rotaing.

Answer 1

according to neuton's law

a object will keep moving until and unless an external force is applies

and planets are in constant orbit because of gravitational force

Answer 2

gravity

Answer 3

Once they are set in motion they are affected by the flux fields of other planets

Answer 4

They are in a continuous state of falling

Answer 5

There is no friction or resistance in space. Once something is moving, it will continue at a steady speed for ever, until something physically slows it down/speeds it up.

Answer 6

The combination of inertia and gravity keeps the planets in their orbits.

Inertia is the tendency of an object to preserve its momentum. In other words: if it's stationary, it will remain stationary untill force is applied to make it move. If it's already moving, it will carry on moving in the same direction untill force is applied to try and change it's movement.

Gravity makes the planets fall towards the sun, but inertia keeps them moving along. The balance of these forces is such that the planets neither fall towards the sun nor fly away from it - they are locked in an orbit around the sun.

Answer 7

While your model is good for demonstrating the concept of an orbit it is also affected by friction due to air resistance and the gravity from the Earth. In space air density doesn't exist as we no it, it is open space after all, and the only major source of gravity is the body your satellite is orbiting around.

The model looks similar but it is not accurate.

Answer 8

planets stay in motion due to the gravity of the sun.The strong gravitational pull of the Sun holds Earth and the other planets in the solar system in orbit.Gravitation is one of the four fundamental forces of nature, along with electromagnetism and the weak and strong nuclear forces, which hold together the particles that make up atoms.

so, as long as the sun lives, the planets and other heavenly bodies inside the solar system will orbit around it.

Answer 9

Well, a mass will stay in motion, the *same* motion, until an external force acts on it.  The planets stay in orbit about the sun, because the gravitational pull of the sun tries to pull it in, but the orbital speed of the planet keeps the body moving.  

Change either - the strength of gravity, or the speed of the planet - and the orbit will fail.  Keep them the same, and the body will continue to orbit as always.  

Answer 10

Due to the law of inertia, gravity and the centrifugal force cause by their rotation around the Sun!

Answer 11

You are forgetting that there is no friction or air resistance in space. They carry on because there is nothing to slow them down.