What is the mass of the ruler moments? (Answer: 127.04g)

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The mass of the ruler moments is determined to be 127.04g. The calculation involves using a force of 2.10N and a distance of 0.29m to find the weight (W) at the center of mass, which is positioned at 0.50m. The derived weight is calculated as 1.22N, equating to approximately 124.5g. Clarification is sought regarding the correct center of mass, noting that the ruler is pivoted at the 1.0 cm mark, indicating a center of mass at 49cm. The discussion emphasizes the importance of accurate measurements and pivot points in calculating mass.
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Homework Statement
Trying to answer the question shown in the picture below. I have to deduce the mass of the ruler.
Relevant Equations
Assuming it’s a moments problem
The answer is 127.04g. I’m getting close but can’t get the answer.

Using 9.81 for gravity, the force where the balance is is 2.10(58146)N

As it is balanced

2.10N x 0.29m = W x 0.50m where 0.50 is the centre of mass

That gives W = 1.22N

= 124.5g?

79E3FA4E-774C-4D13-AAF5-FF5342CAF14D.jpeg
 
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Is 0.50 m correct for the centre of mass?
 
Did you notice the metre ruler was pivoted at the 1.0 cm mark?
 
49cm, thank you!
 

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