Question

how do they keep a satellite in orbit....?do they need energy to move around? or is earths gravitational force enough to give a centripetal force to keep it moving?? i cant understand ,,,,,,,

Answer 1

I see some misconception here..

do they need energy to move around?
ofcourse.. to move u need energy.. which is kinetic energy given by half mv square
but i think what u mean is.. do we NEED TO PUMP ENERGY continuously into these satellites to make them move around?

well to answer that.. if an object is moving in a circular path.. with uniform speed, then its kinetic energy remains a constant.. which means there is no need to do work correct?

but a centrepetal force IS needed to just change the direction of the velocity and not change the Magnitude (speed)..
so for example.. if u take a stone with thread and move around in circles.. initially to get to the stone to speed u need to do work (obviously).. but once it has that .. then u hardly need to move ur finger right? cause theoretically u are just providing the centrepetal force (via the tension of the string .. or in the case of satellites.. the gravitational force of the earth.. they exaactly and one hundred percent similar)

Answer 2

OK....so all they need to do is gather enough energy (fuel) to skyrocket the Satellite Launch Vehicle......and after the sateliite reaches the orbit....completeley forget about it?? then it serves us forever... for FREE?

Answer 3

why do they have solar panels then??

Answer 4

may be to run the inner gadgets,,, iguess?

Answer 5

well.. then u need to push with sufficient speed (which is somewhere around v orbital speed) to make it go around so that it doesn't crash .. cause if take it all the way up and just let it go.. that satellite is not going anywhere but straight down :D :D


now.. what is that u are not getting? huh? u think we are getting something free for nothing?
well since total energy of the satellite remains a constant.. there is nothing that u are getting for free


satellite motion AROUND the earth.. is JUST free fall.. just think.. that satellite is constantly falling towards the earth.. but the satellite is also moving AWAY from the earth .. so as it falls towards the earth.. the earth CURVES away..
so free fall and orbiting is the same damn thing.. think about it ;-)

the diagram shows u ( a giant retricegodzilla of epic proportion) throwing a ball.. first one with low speed, then higher then higher then so high, that it orbits and hits to back from the other end!