How do satellites work?

Question

hey guyz plzz explain the working or motion of satellite in terms of gravitational force

thankzz

Answer 1

Imagine for now that the Earth has no rotation. A satellite directly above London and not moving relative to the Earth would fall directly onto London.

Now imagine a satellite moving at a few metres per second from east to west. It still falls, but because it is moving, it doesn't fall directly onto London.

And now imagine a satellite that is moving extremely quickly. It still is affected by gravitational force, however, by the time it hits where the Earth would be, due to the fact that the Earth is round, there would be no Earth there because the Earth has curved away.

Answer 2

when a satellite is orbiting it is continually falling, but if the velocity is at the right speed when it is thought to hit earth it has moved to far horizontally so that the curvature of earth(for an example) makes it so it never really goes anywhere vertically.

So in shot it falls and falls towards the earth but never really reaches it.  

Answer 3

Satellites are constantly falling but missing the Earth.

Think like this, if I throw a ball (not straight up and down but like at a 45 degree angle) it will go up and then go down and fall some distance away from me.  If I throw it with a larger force, it will fall farther away.  So, if I throw it with enough force, it will go farther than the radius of earth and then there will be no earth for it to fall on and it would want to go into outer space.  But earth's gravity will pull it back and it will start to "fall down" but the initial force will make it keep going and it will miss the earth again.

So the original throw force will make it go horizontally and earth's gravity will make it go vertically but this second force is radial so the ball will end up in a circular motion (it is accelerating).

This means that anything in orbit is actually falling but it keeps missing earth so it doesn't hit it.

Answer 4

Peek here

http://www.howstuffworks.com/satellite.h...

Answer 5

Satellites is first ejected from earth with escape velocity, 11km/s .  In order to launch in its orbit extra calculated energy additional to produce escape velocity is used. After it escapes from earth pull, it rotates in its orbit from the centripital force between earth and satellite. At this point no energy is required to travel in its own orbit.

Geostationary satellites are launched in such a way that it travels in its orbit at same period as earth and remains in same place above earth.  

Answer 6

Sir Isaac Newton, who first described the effect of gravity, explained it this way:

Imagine a cannon sitting on top of a mountain.  The mountain is very tall and the cannon will be above the Earth's atmosphere, so the effects of wind resistance on the cannonball can be ignored.

The cannon fires a cannonball horizontally, so after travelling a distance, the ball will curve downward and hit the ground.  If the firing velocity is increased, as expected, the cannonball travels farther before curving downward to the ground.

If the cannon is fired with sufficient velocity, the ball travels so far that as it falls towards the ground, the curvature of the Earth means that the ground curves away from the ball at at least the same rate.  So the ball continues around the Earth, constantly falling, yet never reaching the ground, in what we call an orbit.

For any specific combination of height above the centre of gravity and the mass of the planet, there is one specific firing velocity that produces a circular orbit.  As the firing velocity is increased beyond this point, a range of elliptic orbits are produced until at a specific velocity called escape velocity, an infinite orbit is produced and the cannonball effectively “breaks free” of the planet's gravity and goes off into space.

If the orbit is at an altitude of 35,786 km (22,236 miles) directly above the equator, the orbital period will be equal to the Earth's period of rotation and a geostationary orbit will be achieved where the satellite appears stationary over a fixed point on the Earth.  This is useful for communications satellites, an idea which was first popularised by Arthur C Clarke, the science-fiction author, in 1945.