Physics Help

[minime72706]

Given the period and mass of a satellite i need to be able to find the altitude, but im not sure how to do that with only two number given. I'm looking for the formulas needed to solve.

A 5500kg satellite orbits earth every 6200 seconds find the altitude and the force of attraction(which i can find after i find the altitude).

Any help is appreciated.
Thanks

 

[91TTZ]

Does the weight even matter in this case? You can have pieces of any size in pretty much any orbit. That's why there's still so much space junk flying around up there. Bolts, washers, debris, etc, can stay in the same orbit as the much larger object it fell off.

With the time it takes to orbit you should be able to find the speed/altitude.

 

[Bootprint]

link

 

[minime72706]

not for finding alt but for force of attraction it does

 

[TheLonelyPhoenix]

F / m = v^2 / r

F = mg

So...

mg/m = v^2 / r

g = v^2/r

...where r is the distance from the center of the earth, and v is the speed of the orbiting object. Since you have the period, you can find the speed very quickly and thus solve for r, then subtract by the radius of the earth to get your altitude.

Edit: And I haven't taken kinematic physics since high school, so it would be great if someone could double-check that for me.

 

[minime72706]

Originally posted by: TheLonelyPhoenix
F / m = v^2 / r

F = mg

So...

mg/m = v^2 / r

g = v^2/r

...where r is the distance from the center of the earth, and v is the speed of the orbiting object. Since you have the period, you can find the speed very quickly and thus solve for r, then subtract by the radius of the earth to get your altitude.

But the speed is depenedt on the distance from earth- the farther out it is the faster it has to go to orbit in 6200 seconds-so its two unkowns

 

[TheLonelyPhoenix]

Originally posted by: minime72706

Originally posted by: TheLonelyPhoenix
F / m = v^2 / r

F = mg

So...

mg/m = v^2 / r

g = v^2/r

...where r is the distance from the center of the earth, and v is the speed of the orbiting object. Since you have the period, you can find the speed very quickly and thus solve for r, then subtract by the radius of the earth to get your altitude.

But the speed is depenedt on the distance from earth- the farther out it is the faster it has to go to orbit in 6200 seconds-so its two unkowns

The velocity while in rotation should be 2*pi*r/6200, so you can plug that in for v instead and solve for r anyway.

 

[minime72706]

Originally posted by: TheLonelyPhoenix

Originally posted by: minime72706

Originally posted by: TheLonelyPhoenix
F / m = v^2 / r

F = mg

So...

mg/m = v^2 / r

g = v^2/r

...where r is the distance from the center of the earth, and v is the speed of the orbiting object. Since you have the period, you can find the speed very quickly and thus solve for r, then subtract by the radius of the earth to get your altitude.

But the speed is depenedt on the distance from earth- the farther out it is the faster it has to go to orbit in 6200 seconds-so its two unkowns

The velocity while in rotation should be 2*pi*r/6200, so you can plug that in for v instead and solve for r anyway.

I fail at reading. I was reviewing the book and found the formula i need r^3=GM(earth)T^2/4*pi^2
Thanks anyways