Geosynchronus Sattelite Question

[bleedblue1234]

Homework Statement

A satellite that stays over the same spot on a planet as it rotates is called a geostationary satellite. (Geostationary satellites must be positioned somewhere over the equator of the planet.) What is the average orbital radius of a geostationary satellite for a planet with a mass of 4.82 x 10^24 kilograms and a period of rotation of 14.0 hours?

Homework Equations

The Attempt at a Solution

F = ma
Fg = GM1m2/r^2
Gm1m2/r^2 = m2(v^2/r)
GM1/r = V^2
GM1/r = (2(pi)/T)^2
GM1/r = 4(pi)^2r^2/T^2
GM1T^2/4(pi)^2 = r^3
r = approx 1.26E8 m

but i am getting it wrong

 

[cepheid]

Looks like a computation error? I get a different answer using that same formula with those same numbers.

 

[bleedblue1234]

Looks like a computation error? I get a different answer using that same formula with those same numbers.

its 10^24... see my post again i edited the question to include the ^

edit... i got 3.34E8 now...

nvm back to 1.26E8

 

[cepheid]

Yeah, I assumed that's what it meant, but I still got a different answer from you.

 

[bleedblue1234]

Yeah, I assumed that's what it meant, but I still got a different answer from you.

hrm so

(6.67E-11) * (4.82 x 10^24) * (14*60*60)^2
/
(4(pi)^2)

so doing the math i get approx
2.01E24 ish

then do the third square root of that to get r...
and i get 1.26E8

 

[cepheid]

hrm so

(6.67E-11) * (4.82 x 10^24) * (14*60*60)^2
/
(4(pi)^2)

so doing the math i get approx
2.01E24 ish

I get approx. 2.06e22.

then do the third square root of that to get r...
and i get 1.26E8

Do you mean the cube root?

It looks like there could be at least two problems with your calculation...

 

[bleedblue1234]

I get approx. 2.06e22.
Do you mean the cube root?

It looks like there could be at least two problems with your calculation...

yes... i meant the cube root

but i am doing the calculation right and i keep getting 2.014E24

(are you doing 14*60*60 to convert hours to seconds?)

 

[cepheid]

http://www.google.com/search?hl=en&...4.82e24)*(14*3600)^2+)/(4*pi^2)&aq=f&oq=&aqi=

 

[bleedblue1234]

http://www.google.com/search?hl=en&...4.82e24)*(14*3600)^2+)/(4*pi^2)&aq=f&oq=&aqi=

hrm... that's weird... so your answer was approx
2.745 E7 m ?
or 2.75 E7 for 3 sf's

o i was forgetting to paranthesize the (14*3600)... that's my problem

 

[cepheid]

Yes, that's about what I got.

 

[bleedblue1234]

Yes, that's about what I got.

about or is... i have 1 submission to get it right...

thanks

edit: nailed the problem, much thanks

 

[cepheid]

about or is... i have 1 submission to get it right...

thanks

edit: nailed the problem, much thanks

Well, you should figure out what you were doing wrong with your calculation and get an answer of your own.

Here is the lazy way of doing it (don't forget to convert to metres):

http://www.google.com/search?hl=en&...kg)*(14+hr)^2)/(4*pi^2)+)^(1/3)&aq=f&oq=&aqi=