Need universal Gravitation help

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Homework Help Overview

The discussion revolves around understanding the gravitational force equations as applied to specific scenarios depicted in attached diagrams. Participants are examining the gravitational force formula, Fg = G M*M/D^2, and its variations based on different setups presented in the images.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants are attempting to identify the origins of coefficients in the gravitational force equations, specifically questioning how the factors of 2 and 6 are derived. There is also a focus on the definitions of the masses involved and their representation in the diagrams.

Discussion Status

The conversation is ongoing, with some participants expressing confusion about the coefficients in the equations and seeking clarification on the mass labels in the diagrams. Others have provided insights into how to interpret the equations based on the images, but there is no explicit consensus on the derivation of the coefficients yet.

Contextual Notes

Participants note that the diagrams do not specify the masses as M1 and M2, leading to further questions about how to label and interpret the variables in the gravitational force equations.

Combine
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Homework Statement


what is the magnitude of Gravitational force
for the following picture(s)
(attached to forum)

Homework Equations


Fg = G M*M/D^2


The Attempt at a Solution


I tried to do some of them I know the equation for the second one is fG = 2G M*M/D^2
and for the third one it's Fg = 6G M*M/D^2
But I have no idea where the 2 came from for the second one and the 6 from the third one!
 

Attachments

  • Questions.png
    Questions.png
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Combine said:

Homework Statement


what is the magnitude of Gravitational force
for the following picture(s)
(attached to forum)

Homework Equations


Fg = G M*M/D^2


The Attempt at a Solution


I tried to do some of them I know the equation for the second one is fG = 2G M*M/D^2
and for the third one it's Fg = 6G M*M/D^2
But I have no idea where the 2 came from for the second one and the 6 from the third one!

A better way to write that force is F = G M1 M2 / D^2, where M1 and M2 are the two masses. Does that help?
 
Kinda, I still don't understand where the 2 in fG = 2G M1 * M2/D^2
or the 6 in fG = 6G M1 * M2/D^2 come from
 
Combine said:
Kinda, I still don't understand where the 2 in fG = 2G M1 * M2/D^2
or the 6 in fG = 6G M1 * M2/D^2 come from

In the 3rd one, what are M1 and M2?
 
According to my sheet, it's just simply m1 and m2, there are no mass representing them, I think you just have to write the final equation
 
Combine said:
According to my sheet, it's just simply m1 and m2, there are no mass representing them, I think you just have to write the final equation

attachment.php?attachmentid=37175&stc=1&d=1310606192.gif


There are two masses and a distance indicated. Call the mass on the left M1, and the mass on the right M2. What are M1 and M2 according to the figure? What is the distance?
 

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  • Fig1.gif
    Fig1.gif
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there is no mass specified it just says M1 and M2 and distance is just represented by d
 
Combine said:
there is no mass specified it just says M1 and M2 and distance is just represented by d

Look more closely at the diagram. I don't see the characters "M1" or "M2" in the figure. How are the masses labelled?
 
Never mind my teacher answered the question for me (after several rather painful hours of waiting) we just have to make the equation nothing special, Fg = 6G M1 * M2 / d
and he also explained to me what the 6 was...

I am such an idiot >.<
thanks for the help though
 
  • #10
You just insert the numbers in the pictures into the equation. For example:

The second one - [itex]F=\frac{G2mM}{{\Delta}d^{2}}[/itex]

Which also is equal to - [itex]F=\frac{2GmM}{{\Delta}d^{2}}[/itex]

Basically, you take the number of the specific mass or [itex]{\Delta}d[/itex] and multiply it or divide it by the appropriate amount as represented by the picture.

The third one is [itex]F=\frac{G2m_{1}3m_{2}}{{\Delta}d^{2}}[/itex] and it simplifies to [itex]F=\frac{6Gm_{1}m_{2}}{{\Delta}d^{2}}[/itex]EDIT: Ah whoops, I replied to late...
 

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