A satellite doesnt need any energy to revolve around the earth. Why?
SIMPLY PUT IT FALLING IN A CIRCLE SO HOW MUCH ENERGY DOES IT TAKE TO FALL ANSWER ZERO Throw anything up , it falls ,,,did it take some energy to make it fall ? NO Picture it this way if you shot a bullet toward the horizon it would go a long way and while falling back and hits the ground ,,,,,if you shoot it faster it goes farther before it hits If you shoot it at 22,500 mph it goes so far it can't fall enough to come back to earth this is stays falling and keeps going around the earth It has achieved orbit and as other state the force of the centrifugal force of the curved path = the force of gravity The calculations to prove this are in Physics books To break in to orbit for the Earth an object must go faster than 22,500 mph faster speeds are higher orbits ,,,,slower speed the orbit is not achieved and as said there is little to slow an object in orbit thus the speed stays for a long time there is some drag so in time an orbit can decay , that decay rate depends on it height An object like the moon has been in orbit for millions of years !!! low orbits like 200 miles might only last 7 to 10 years ,,,,because they do hit into a little air which slows that low orbit object There can be a partial orbit like a missle where it almost makes an orbit , it might be moving at 19,500 mph so it goes very high 200 miles or just over a million feer , then comes right back to Earth during this time it has traveled some 10,000 mile in 30 minutes to say Iran and nukes its a s s out This is the reason the USA could launch 100 missiles and wipe out Iran in less than a half hour and with over 10,000 missiles could remove the entire Arab world in 30 min
A satellite does not need any energy to revolve around the Sun. Why?
Because an object in motion will not change its velocity unless a force acts upon it.Newton's laws of motion - WikipediaIn an orbit, the gravitational force changes the velocity mostly by changing its orientation (so the object ends up describing an ellipse). Any change in the velocity’s magnitude is periodical, adding as the object draws nearer to the Sun, subtracting as it draws farther.Energy losses due to solar light pressure, solar wind friction, the Poynting-Robertson effect or gravitational radiation are all utterly negligible.
Why do satellites need no energy to revolve around the Earth?
“Why do satellites need no energy to revolve around the Earth?”Satellites do need energy in order to get to the point where they can orbit, but do not need additionally energy when they get there for a good reason.As I’m sure you’re aware, space does not have any atmosphere. The Earth does. For this simple reason, if you tossed something on Earth fast enough in order to revolve around the Earth just perfectly if there was no atmosphere, the ball would fall short. As the ball is no longer being propelled, and is simply now moving, the air starts to put resistance on it. It isn’t like the ball hit a wall when it gets to the atmosphere, but more like a liquid. The air molecules hit the molecules of the ball, taking away energy and slowing the ball down to a stop.Now, if you went up into space, and through the ball again to spin around the Earth, because there is no air resistance, the ball continues to move at the same speed as it did when you through the ball, and will continue to do so until it is acted upon.This was one of Newton’s laws of motion, as an object in motion stays in motion unless it is acted upon.
I) Why artificial satellite does not need any fuel to revolve around the earth .?
Because it was launched in orbit and the gravitational force from earth makes it stay there.
Does the artificial satellites need energy to revolve around earth? If no then why don't the friction due to air stop it finally?
Look up Newton's Cannonball for a good illustration of orbital motion. Orbital motion is not powered flight and the fuel on-board artificial satellites - once they have reached their final orbit - is for stationkeeping and attitude control and not for powered flight. (By contrast, aircraft have powered flight - the engines are running for the entire time the aircraft is in flight.) The earth's atmosphere extends up to almost 1000 kms. However, beyond about 100 kms the air density drops to a point where the amount of friction is not very high. The definition of low earth orbit is up to 2000 kms of altitude. Most spy satellites operate in very low earth orbit, in the 100 - 250 kms region. At that altitude, they lose enough altitude due to atmospheric friction that they need to boost themselves up time and again. However, international space station which operates at about 350 kms faces much less friction. Space shuttles used to operate in the 250 - 500 kms zone. So beyond 250 kms or so, atmospheric friction is not a significant issue.
Where does the earth get the energy to revolve around the sun?
The Earth revolves around the sun from the gravity caused by the attraction of the Sun and Earth to one another. There is no energy transferring here, both objects continue to have the same energy they began with. The reason why the Earth simply doesn't collide into the Sun is because of the fairly stable orbit that the Earth has around the Sun. These two massive objects are basically "falling" towards one another, constantly, but thanks to centripetal force, they create an stable orbit which allows them to continue to do this for a very long time.To explain a bit more how the above situation came to be: when two objects near each other for the first time, they exert gravitational force between each other. This force causes both objects to be attracted to one another. This happens for ALL objects, regardless of the mass, although objects with larger mass cause more significant gravitational force. A 150 lbs human being exerts a gravitational force on the objects around it, but it is so weak that it's virtually undetectable. The Earth, on the other hand, is so large, that it creates a gravitational force capable of keeping us all weighted down to the ground (instead of flying off into outer space). In space, when two objects near each other, the forces can have a variety of effects. In the objects are too close, the gravitational force could accelerate them into one another causing a direct collision. This happens quite often, and in the case of the Sun and the vast majority of things that collide into it, the other object simply burns up and is absorbed by the Sun. On the other hand, if an object is far enough away to avoid a collision, but still close enough to be affected significantly by the Sun's gravitational force, it can enter an orbit around the Sun by "constantly falling" towards the Sun. The net force of the object's original velocity trying to move away from the Sun, combined with the force of the two objects' gravitational pulls on each other, causes them to begin circling one another. In the vast majority of cases, other objects are significantly smaller than the Sun, so you won't see the Sun move a whole lot due to the other object, BUT the Sun is still moving slightly. (This is actually how astronomers can detect various qualities of far away stars, based on very slight movements in those stars.)
Do we need energy to keep a satellite in an orbit around the Earth?
Hello RahulThanks for A2ATheoretically, we do not need to spend any energy to keep a satellite orbit the Earth. But in practical, things are a bit different.You must have heard about something known as course correction in satellite launching rockets. They basically shift their course, aligning to their target in case any anomaly occurs.Similarly, the same concept applies to orbiting satellites. Due to the exact balancing of gravitational and centripetal force, a satellite can orbit the Earth freely. But in case of any anomaly, the thrusters(if present on the system) can be used to get it back on its course.Hope this helps!
A satellite revolves around Earth in a circular orbit. Does Earth's gravity do any work on the satellite?
Work is force X displacement. I cannot find the displacement due to gravity in this question. Gravity is pulling down on the satellite in the direction of the center of the earth. That would always be perpendicular the the velocity of the satellite. If the satellite is in a constant orbit. It stays the same distance from the center of the earth. No displacement along the line of force due to gravity. So, No. HTH - hope this helps.
Can we launch a satellite so that it could revolve around mars?
We have already done it. Mariner 9, Vikings 1 and 2 were previous orbiters. Vikings had landers also. Currently five satellites are orbiting Mars viz. Mars Odyssey, Mars Express, Mars Reconnaissance Orbiter, MAVEN and Mangalyaan from ISRO.