Tuesday, July 24, 2007

Satellites and "Weightlessness"

A satellite is put into orbit by accelerating it to a sufficient high tangential speed with the use of rockets.

If the speed is too high, the spacecraft will not be confined by the Earth's gravity and will escape, never to return.

If the speed is too low, it will return to Earth.

Satellite are usually put into circular (or nearly circular) orbits, because such orbits require the least takeoff speed.






this image is from www.howstuffworks.com

If a satellite stopped moving, it would fall directly to Earth.

But at the very high speed a satellite has, it would quickly fly out into space, if it weren't for the gravitational force of the Earth pulling it into orbit.

In fact, a satellite is falling (accelerating toward Earth), but its high tangential speed keeps it from hitting Earth.













1 comment:

ဘလူးဖီးနစ္ said...

မမ ေရးထားတာေတြကို စိတ္၀င္စားတယ္။ ျမန္မာလိုရွင္းျပရင္ပိုေကာင္းမယ္သိလား။ ကြၽန္ေတာ္က အဂၤလိပ္လိုဖတ္ရတာ ပ်င္းလို႔ပါ။