Physics
posted by Frederico Barreto .
I really need you answered this to my email. It's very important, for this may decide my result in the school exams, and I really need a good mark.
Unfortunately, Portuguese system of education is full of problems...
The question is...
The altitude of a geostationary satellite depends on:
a) … the satellite’s mass.
b) … the absolute value of its speed
(Considering this is a circular motion)
c) … the Earth’s mass.
d) … the launching speed of the satellite (speed which he was thrown)
Consider while in orbit, there are one force operating on the satellite: Gravity. To be in orbit, gravity must equal exactly the "force" expected in centripetal acceleration.
Gravity Force= centripetalforce
GMeM/r^2= M v^2/r
dividing out M, the mass of the satellite, and r , one has
GMe/r= v^2 or
r= v^2/GMe so the factors are velocity in orbit, and the mass of the Earth.
The altitude of a geostationary satellite depends on:
a) … the satellite’s mass.
b) … the absolute value of its speed
(Considering this is a circular motion)
c) … the Earth’s mass.
d) … the launching speed of the satellite (speed which he was thrown)
How do you determine the altitude at which a satellite must fly in order to complete one orbit in the same time period that it takes the earth to make one complete rotation?
The force exerted by the earth on the satellite derives from
...................................................F = GMm/r^2
where G = the universal gravitational constant, M = the mass of the earth, m = the mass of the satellite and r = the radius of the satellite from the center of the earth.
GM = µ = 1.407974x10^16 = the earth's gravitational constant.
The centripetal force required to hold the satellite in orbit derives from F = mV^2/r.
Since the two forces must be equal, mV^2/r = µm/r^2 or V^2 = µ/r.
The circumference of the orbit is C = 2Pir.
A geosycnchronous orbit is one with a period equal to the earth's rotational period, which, contrary to popular belief, requires 23hr56min4.09sec. to rotate 360º, not 24 hours. Therefore, the time to complete one orbit is 23.93446944 hours or 86,164 seconds
Squaring both sides, 4Pi^2r^2 = 86164^2
But V^2 = µ/r
Therefore, 4Pi^2r^2/(µ/r) = 86164^2 or r^3 = 86164^2µ/4Pi^2
Thus, r^3 = 86164^2(1.407974x10^16)/4Pi^2 = 2.647808686x10^24
Therefore, r = 138,344,596 feet. = 26,201.6 miles.
Subtracting the earth's radius of 3963 miles, the altitude for a geosynchronous satellite is ~22,238 miles.
Respond to this Question
Similar Questions

Need help in business studies, econ or computing?
I'm a CIE (Cambridge International Exams) A Level student who gave her A2 exams in October... *expecting results this month*... Anyway, my subjects were Economics, Business Studies and Computing. I got good grades in my AS exams, and … 
English Language
I asked this question earlier. I need to write 2 letters of complaint about problems I face at school and problems I face as a student in general but I can't find any problems, could you help me list some problems? 
check please
hi ms. sue i was wondering if you had email that i can have to email you if i need help because i need help with accounting with some type of graph but it wont fit here is there anyway you could help me through your email or i can … 
English
I left out two sentences I need to write in an email. 1) I wrote to the two Irish school's principals you suggested (to me) but none of them replied to my email. 2) As I would really like to start a school exchange programme with an … 
English
Thank you very much, Writeacher. Could you please check these sentences I need to include in an email? 
English
Writeacher, you didn't manage to check my post yesterday. I really need you to check just this part. I also included a few other things. Thank you very much in advance! 1) Mr. Gradgrind turns his attention to Bitzer, perhaps because … 
English
I urgently need you to help me find the proper words. Thank you Writeacher 1) Thank you very much for sending me the list of your students. I was thinking of creating a link to our partnership ( I don't know how to express this) on … 
Science Fair Project
Please help any tutors around, i really need help on what topic to choose, and my science fair is in February 16, 2015!!!!!! I just want to get a really good mark so i get an A in Science again this year in my report card. From a Student … 
6th Grade Science
Hi, I really need help and I'm really confused I don't know what they are asking me to do. Provide three statements that demonstrate the importance of units when describing motion. Please someone help me because it is very important. … 
Science
Without this system in the body, you would get really sick because toxins and waste would build up?