Speed of satellite in circular orbit

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The discussion focuses on calculating the speed of a satellite in a circular orbit around Earth, given its mass and orbital period. The initial calculations for the radius and speed were incorrect, but after re-evaluating, a radius of approximately 46,357,704 meters was determined. The final speed of the satellite was calculated to be 2,933.27 m/s, which was confirmed by another participant as correct. The conversation highlights the importance of careful calculation in orbital mechanics. Overall, the correct speed of the satellite is 2,933.27 m/s.
thatgirlyouknow
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Homework Statement



A satellite is in a circular orbit about the Earth (M = 5.98 x 1024 kg). The period of the satellite is 9.93 x 104 s. What is the speed at which the satellite travels?

Homework Equations



v=(2*pi*r)/T

v=sqrt((GMe)/r)

The Attempt at a Solution



sqrt[((6.67x10^-11)*(5.98x10^24))/r) = 2*pi*r / T
T = 2piR^3/2 / (sqrt[GMe])
r = 8.414 x 10^15
v = 2*pi*r / t
v = 5.324 x 10^11 m/s
 
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thatgirlyouknow said:

Homework Statement



A satellite is in a circular orbit about the Earth (M = 5.98 x 1024 kg). The period of the satellite is 9.93 x 104 s. What is the speed at which the satellite travels?

Homework Equations



v=(2*pi*r)/T

v=sqrt((GMe)/r)

The Attempt at a Solution



sqrt[((6.67x10^-11)*(5.98x10^24))/r) = 2*pi*r / T
T = 2piR^3/2 / (sqrt[GMe])
r = 8.414 x 10^15

your formula looks right but I think r is wrong... check your calculations
 
Ok after reworking I got that r = 46357704 m. So:

v = sqrt[(GMe)/r]
v = sqrt[(6.67x10^-11*5.98x10^24)/(46357704)]
v = 3594.51 m/s

But this still isn't right. Are my calculations wrong at some point?
 
Ok I worked it again and got v = 2933.27 m/s. (Hooray human error). Can anyone verify that as correct?
 
thatgirlyouknow said:
Ok I worked it again and got v = 2933.27 m/s. (Hooray human error). Can anyone verify that as correct?

yes, looks right to me.
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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