Space Calculations (1 Viewer)

[x.Exhaust.x]

I am having a few problems with the following space calculations. If anyone can provide working out with explanations, that'd be great . Thanks.

A 2000kg satellite is in a circular orbit 225km above the Earth's sruface. Given that the mass of Earth is 6.0x10^25kg and the radius of Earth is 6.38x10^6.

a) What is it's orbital speed?

v= sqrt. GM/r

v= sqrt.(6.67x10^-11x6.0x10^24/(6.38x10^)

How can I introduce the satellite into my working out?

b) What is it's orbital period?

r^3/T^2=GM/4pie^2

(6.38x10^6)^3/T^2=(6.67x10^-11x6.0x10^24)/4pie^2

T=5061.45 seconds

The answer is 5331.51 seconds .

Calculate the centripetal force acting on it.

Fc=mv^2/r

I think the satellite included owned me (not sure how to add it and all).

 

[Pwnage101]

orbital velocity is independant of the amss of the satellite orbiting

also, 'r' is the distance between the satellite and earth - u have to ADD the radius of the earth AND the altitude of the satellite, so in your calculations r DOES NOT equal 6.38x10^6m, but rather :

r= 6.38x10^6 + 225 000 = 6.605x10^6 m

if you use this figure, the asnwer to (b) does turn out as 5,331.51

with Fc=mv^2/r

m= mass of satellite = 2000kg

v= orbital velocity, whcih is calculated in (a), and r is 6.605x10^6 m

just to recap, the answers are:

(a) = 7 784 m/s

(b) = 5331.51 s

(c) = 1 8347 N

 

[x.Exhaust.x]

Thx pwnage.