Centripetal Acceleration of a Satellite Orbiting Saturn

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Homework Help Overview

The discussion revolves around calculating the centripetal acceleration of a satellite orbiting Saturn at a specific altitude, which is one Saturn radius above its surface. Participants explore the relationship between gravitational acceleration and centripetal acceleration in this context.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning, Assumption checking

Approaches and Questions Raised

  • Participants discuss the formula for centripetal acceleration and its connection to gravitational acceleration. There are questions about the dimensions of certain equations and how to equate gravitational force with centripetal force. Some participants express confusion about the variables involved and the information required for the calculations.

Discussion Status

There is an ongoing exploration of the relationship between gravitational intensity and centripetal acceleration. Some participants have provided insights into the calculations and the necessary variables, while others are still seeking clarity on specific aspects of the problem. The discussion reflects a mix of attempts to understand the underlying principles and the mathematical relationships involved.

Contextual Notes

Participants note that certain values, such as the mass and radius of Saturn, are not provided in the problem statement, leading to questions about how to proceed with the calculations. There is also mention of potential discrepancies in values derived from different sources.

Coco12
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Homework Statement



What is the centripetal acceleration of a satellite orbiting Saturn at the location exactly one Saturn radius above the surface of Saturn

Homework Equations


Ac=v^2/r
In the previous question found out that the fg at that location is 1/4 of 36.0 N



The Attempt at a Solution


I read somewhere that they made centripetal acceleration equal to Gm/4pi ^2

But why?? How are those two linked?
 
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Coco12 said:

Homework Statement



What is the centripetal acceleration of a satellite orbiting Saturn at the location exactly one Saturn radius above the surface of Saturn

Homework Equations


Ac=v^2/r
In the previous question found out that the fg at that location is 1/4 of 36.0 N



The Attempt at a Solution


I read somewhere that they made centripetal acceleration equal to Gm/4pi ^2

I would not lend much credulity to what you read. The dimensions of Gm/4pi^2 are not the dimensions of acceleration.

Equate gravitational acceleration to centripetal acceleration.
 
rude man said:
I would not lend much credulity to what you read. The dimensions of Gm/4pi^2 are not the dimensions of acceleration.

Equate gravitational acceleration to centripetal acceleration.

The answer is the same as the gravitational intensity which is 2.60N . How does that work??
 
Coco12 said:
The answer is the same as the gravitational intensity which is 2.60N . How does that work??

Not too well. Acceleration is not measured in Newtons either ...
 
Then how do u do this question?
 
I have two masses m1 and m2. What is the (gravitational) force of m1 on m2 (or m2 on m1)?

Picking the force on m2, then use F = ma on m2. Your answer is a. What is gravitational F?
 
The mass being saturn's mass?
 
Well, you have two masses to consider, the satellite's mass and Saturn's mass. After you make some cancellations in your equations, you may not need both values, though.

Anyway, if this satellite is in orbit, it's experiencing a centripetal force. The real question: what force IS PROVIDING this centripetal force? What's the equation for this force that rude man is getting at? Equate this to your centripetal.
 
zahbaz said:
Well, you have two masses to consider, the satellite's mass and Saturn's mass. After you make some cancellations in your equations, you may not need both values, though.
Anyway, if this satellite is in orbit, it's experiencing a centripetal force. The real question: what force IS PROVIDING this centripetal force? What's the equation for this force that rude man is getting at? Equate this to your centripetal.

Mv^2/r=gm1m2/r^2?
 
  • #10
Coco12 said:
Mv^2/r=gm1m2/r^2?

How come three different masses?
 
  • #11
rude man said:
How come three different masses?
Oh no, the m in the first equation is the same as m1 in the equation after the equal sign.

So when canceled would be: v^2/r=Gm/ r^2?
 
Last edited:
  • #12
Coco12 said:
Oh no, the m in the first equation is the same as m1 in the equation after the equal sign.

So when canceled would be: v^2/r=Gm/ r^2?

Looking better.
So which is your m? The planet or the satellite? And what is r?
 
  • #13
Mass would be the mass of Saturn and radius would be the radius of Saturn *2? The thing is , all of this info is not given in the problem, so how are we supposed to know it?
 
  • #14
Coco12 said:
Mass would be the mass of Saturn and r would be the radius of Saturn *2?

Yes.

The thing is , all of this info is not given in the problem, so how are we supposed to know it?

Take a trip to Saturn? Dunno, but you need both the mass and the radius of Saturn.
 
  • #15
i will try it out and see whether I can it.
 
  • #16
I tried it out and did not get the answer. Could it be any way that the gravitational field intensity is equal to the centripetal acceleration, since in the book, the answer to both is the same
 
  • #17
What's the book's answer? I was anticipating the reasoning you said you followed.

Below I pulled Saturn's mass and radius from Google, thought if it's a book problem, I'm sure your text has similar values printed inside.

mv^2/r = GmM/r^2
v^2/r = GM/r^2
where M = mass of saturn = 568.3 x 10^24 kg
r = two saturn radii = 2(58,232,000 m)
a = GM/r^2
a = 2.79 m/s^2
 
  • #18
zahbaz said:
What's the book's answer? I was anticipating the reasoning you said you followed.

Below I pulled Saturn's mass and radius from Google, thought if it's a book problem, I'm sure your text has similar values printed inside.

mv^2/r = GmM/r^2
v^2/r = GM/r^2
where M = mass of saturn = 568.3 x 10^24 kg
r = two saturn radii = 2(58,232,000 m)
a = GM/r^2
a = 27.9 m/s^2

The answer is 2.60 m/s^2 which is the same as the gravitational intensity
 
  • #19
What is this gravitational intensity you keep bringing up?

PS... I edited my post in the time you replied. I had made a calc error. I got a = 2.79 m/s^2, which is pretty close to 2.60m/s^2. I'm wondering if your book has different, perhaps rounded values for Saturn's mass and radius.
 
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  • #20
zahbaz said:
What is this gravitational intensity you keep bringing up?

PS... I edited my post in the time you replied. I had made a calc error. I got a = 2.79 m/s^2, which is pretty close to 2.60m/s^2. I'm wondering if your book has different, perhaps rounded values for Saturn's mass and radius.

This was a two part question. In the first it asked for gravitational intensity.
 
  • #21
I think that might be the case. I got the 2.79 m/s^2 too.
 
  • #22
Oh okay... So gravitational intensity is gravitational force per unit mass... otherwise stated as F/m.

We know gravitational force is GmM/r^2, so therefore gravitational intensity is GM/r^2. Which is... ta dah! The same thing we had before!

Yeah, I'm not sure what digits were used in the prior calculation that got you 2.60m/s^2, but the theory is identical in both approaches. If it was a two stage problem, I'd stick with the 2.6.
 
  • #23
zahbaz said:
Oh okay... So gravitational intensity is gravitational force per unit mass... otherwise stated as F/m.

We know gravitational force is GmM/r^2, so therefore gravitational intensity is GM/r^2. Which is... ta dah! The same thing we had before!

Yeah, I'm not sure what digits were used in the prior calculation that got you 2.60m/s^2, but the theory is identical in both approaches. If it was a two stage problem, I'd stick with the 2.6.


Wow! Thank you! I understand where it comes from now!
 
  • #24
Post #17 answer is close to yours so the difference is probably due to differences in what you & he/she used for M and r.

What is "gravitational intensity"? I never heard that term used in lieu of gravitational acceleration.
 

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