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Significance of Gravitational Force (view source)
Revision as of 11:48, 4 December 2013
, 11:48, 4 December 2013→Notes for teachers
This is very similar to the sense of loss of weight in a lift that is accelerating downwards - except that here the acceleration is the acceleration due to gravity.<br><br>
This is very similar to the sense of loss of weight in a lift that is accelerating downwards - except that here the acceleration is the acceleration due to gravity.<br><br>
'''An Earth Satellite'''
An Earth satellite is simply a projectile that falls around the Earth rather than into it. That means the horizontal falling distance matches the Earth''s curvature. Geometrically, the curvature of the surface is that its surface drops a vertical distance of 5 metres for every 8000 metres tangent to the surface.
Therefore, if we throw a rock or a ball at a high enough speed (about 29000 km/s), it would follow the curvature of the Earth. But at this speed, atmospheric friction (due to air drag) would burn up everything. This is why satellites are launched at an altitude high enough for the air drag to be negligible.
Satellite motion was understood by Newton who reasoned that the Moon was simply a projectile that was circling the Earth. <br><br>
===Activity No # 1 Simulation of a projectile===
===Activity No # 1 Simulation of a projectile===