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View Full Version : Calculating energy of a geosynchronous satellite


mikee
Feb27-08, 01:55 AM
1. The problem statement, all variables and given/known data

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hey i was just wondering if i was on the right track here, the question is calculate the total energy(E) of a geosynchronous satelite (that orbits around a fixed spot) with a mass of 1500kg orbiting earth at a height of 325km with an orbital speed of 5000 m/s,

2. Relevant equations

ok i was taught that Total E = Kinetic E + Potential E, and also that Kinetic E= 1/2mV^2 and Potential E= mgH

3. The attempt at a solution
ok i took into account that gravity would not be 9.8 so
i calculated what it would be Using Fg=Gm1m2/d^2 and i came up with 1.32x10^4,also note that to calculate distace i added 325km to the radius of the earth, then i plugged
in 1/2(1500)(5000)^2 + 1.32x10^4(1500)325000 = Total E, does this seem correct? thanks

mgb_phys
Feb27-08, 02:43 AM
Remember energy is force * distance and so gravitatonal potential energy = GMm/r

kamerling
Feb27-08, 09:35 AM
There is a problem with the question. Geosynchronous satellites do not orbit at 325 Km height. And a satellite at 325km with an orbital speed of 5000m/s will fall back to earth.