What is the Mass of the Ruler on a Sharp Edge?

AI Thread Summary
To determine the mass of the ruler, the forces acting on it must be analyzed, particularly the downward force due to its weight. The stone exerts a force of 0.981N, and the ruler balances at a point 15.0cm from one end. By applying the principle of moments, the moments around the pivot point can be equated to find the mass of the ruler. The calculations require considering the distances from the pivot to both the stone and the center of mass of the ruler. The final mass can be calculated using these principles of equilibrium and moments.
Miri
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Turning effects of forces 3

Homework Statement


A ruler of an unknown mass is 52.0cm long. To find out its mass, you put a stone of 100g on the ruler 3.0cm from its end and balance the ruler on a sharp edge. The ruler is balanced when the supporting edge is 15.0cm from its end. Calculate the mass of the ruler.


Homework Equations


I know that the force of the stone is 0.981N. But what do I have to do to find out the force pointing downward of the ruler, so that I can find the mass...?
 
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Miri said:

Homework Statement


A ruler of an unknown mass is 52.0cm long. To find out its mass, you put a stone of 100g on the ruler 3.0cm from its end and balance the ruler on a sharp edge. The ruler is balanced when the supporting edge is 15.0cm from its end. Calculate the mass of the ruler.


Homework Equations


I know that the force of the stone is 0.981N. But what do I have to do to find out the force pointing downward of the ruler, so that I can find the mass...?
This question is very similar to your other thread, turning forces 4 and can be tackled in a very similar manner.
 

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