where do planets get their energy from to sustain their perpetual motion?

Answer 1

Planets fly around in outer space in no atmosphere. There is no air out there, meaning there is no resistance to their motion. So it's not so much a case of 'sustaining their perpetual motion' as having nothing to stop them.

Answer 2

Isaac Newton deduced that "An object at rest tends to stay at rest and an object in motion tends to stay in motion with the same speed and in the same direction unless acted upon by an unbalanced force." As the planets formed from the accretion of debris there would be velocity and direction. As the sun has a huge mass, it exerts a gravitational force on lesser bodies, thus pulling the planets, travelling at a fixed velocity (due to frictionless vacuum of space) in an orbit around the sun. This will not change, unless some other force is applied, for example Nasa uses the planets' gravity to sling shot at greater speed to the outer solar system. The planet will slow by the amount the craft speeds up ie every action has an equal and opposite reaction.
Amazing innit!

Answer 3

planets dont move in perpetual motion. They are in orbit, in circular motion. This means they have an acceleration towards their center of gravity but have a velocity that is perpendicular to it. This means no work is done on the planet, so the orbit can be maintained without an input of energy.

Answer 4

Gravity controls the planets energies and also force fields. It's like a manetic pull of the sun one example is, Heat causes energy the suns rays gives off heat thus energy is released. The planets gets gravity from the sun and the sun provides heat to warm the planet and also supplies energy to the planet.

Answer 5

Momentum, plain and simple. In space there is no drag, so planets keep going at the same speed they have already. Energy remains constant, speed stays essentially the same.

Actually, in space, there IS a little drag, mostly in what we call tidal effect, but oddly enough, tide transfer spin energy from the earth to orbital energy tgiven to the moon. Millions of years ago, the earth was spinning faster (days were shorter than 24 hours) and the moon was closer.

Answer 6

It's from the Big Bang and after that,the planets keep moving because there's no air resistance to slow them down. Gravity keeps them in an orbit around the Sun,but our Solar System itself is still moving further apart.

Answer 7

Planets, moons, and stars spin without any fuel, batteries, muscle, cost, or other limited power. Planets don't rotate forever however; energy in such system is dissipated via tidal forces, by friction with the dust and gas in space, and perhaps also very slowly via gravitational waves.

You did ask lol :-)

Answer 8

Good Lord. Do they not teach you basic Newton's laws in science?

Things stay in steady motion unless something is present to accelerate them or decelerate them.

In the case of the planets, satellites, comets, asteroids, stars, - in most cases, they have few forces trying to alter their motion.

On earth, we suffer from friction - the surfaces and the air. In space, far away from gravitational influences, if you throw a ball, it will go on for ever. If in throwing it, you impart a spin to it, it will also spin for ever.

Also, since Newton also said that action and reaction are equal and opposite, when you throw the ball in space, you will be propelled in the opposite direction.

PS - Newton was not as spacially cognisant as Einstein in later times. When he talks about objects at rest, as the last respondant mentioned, that does not apply in space. Relativity dictates that in space, nothing is at rest - everything is moving relative to everything else.

Answer 9

Gravity and the vacuum or space. Because the planets are in an orbit, there is nothing to slow them down because there is no friction.

(Planet = O)
(Stop = | )
In space
O ----------------->
(continues forever around a strong point of gravity e.g the sun)

In an atmosphere
O -----|

(Will slow down due to particles hitting surface, causing friction)

Answer 10

Gravity