Discovering the Mass of an Object on a Ruler Using Known Variables - Find M_2

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Homework Help Overview

The problem involves a ruler with a pivot at its center, where one known mass (M_1) is placed at a distance (L_1) from one end, and an unknown mass (M_2) is positioned at the end of the ruler. The goal is to express the unknown mass in terms of the known variables.

Discussion Character

  • Exploratory, Assumption checking

Approaches and Questions Raised

  • Participants discuss the relationship between the masses and their distances from the pivot, referencing the equation M_1*L_1 = M_2*L_2. There are attempts to manipulate this equation to find M_2, but some participants express confusion regarding their calculations and the definitions of L_1 and L_2.

Discussion Status

The discussion is ongoing, with participants seeking clarification on their attempts and questioning the correctness of their expressions for L_1 and L_2. There is no consensus yet, but the dialogue indicates a willingness to explore different interpretations of the problem setup.

Contextual Notes

There appears to be some confusion regarding the definitions of distances L_1 and L_2, as well as the implications of the pivot's position on the calculations. Participants are trying to reconcile their understanding of the problem with the provided equation.

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urgent help needed to finding the mass

Homework Statement


We have a ruler with a total length L_r and a pivot at its middle. An object of known mass M_1 is placed a distance L_1 from the end of the ruler, as shown. An object of unknown mass M_2 is placed at the end of the ruler.

http://session.masteringphysics.com/problemAsset/1010957/18/MFS_to_6_b.jpg

Find the mass M_2.
Express the mass in terms of M_1, L_1, and L_r.


Homework Equations



M_1*L_1 = M_2*L_2

The Attempt at a Solution


i tried doing ((M1)*0.5*(Lr)) / (L1 - 0.5Lr) but that's wrong and i don't understand why...
 
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channel1 said:
M_1*L_1 = M_2*L_2

The Attempt at a Solution


i tried doing ((M1)*0.5*(Lr)) / (L1 - 0.5Lr) but that's wrong and i don't understand why...

L_1 is L1-0.5Lr and L_2 is 0.5*Lr
 

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