What is the Mass of Meter Stick in Sketch?

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The discussion centers on determining the mass of a meter stick balanced on a fulcrum, with multiple choice answers provided. Participants express confusion over the concept of torque and the mass distribution along the meter stick. The solution involves treating the meter stick as massless and calculating the torque based on weights placed at specific points. Ultimately, the correct mass of the meter stick is identified as 120 grams. The conversation highlights the challenges faced by students in understanding basic physics concepts.
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Homework Statement


What is the mass of the meter stick, which is shown in the sketch below while it is balanced?

http://img252.imageshack.us/img252/9819/problemeo4.jpg
a 160 grams b 120 grams c 80 grams d 200 grams e none of the above

Homework Equations





The Attempt at a Solution



I am completely CONFUSED! Our professor never discussed finding the mass of the lever.
 
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The meter, you can think of like a mass that adds torque to the system. Consider the each side of the meterstick as a mass concentrated at that center of gravity for the side. Then you can solve for the sum of the torques = 0.
 
To reiterate what thepanda said, think of the leaver as mass less, and simply assume there is a mass of "x" weight hanging from the 50cm mark of the meter stick (20cm to the right of the fulcrum). Simply solve for "x".

*It is placed here because it is the object's center of mass
 
Okay I know I am going to sound completely stupid, but I am still getting really confused. I have a political science degree and working on a history degree. I am in the lowest level physics and I am still getting really confused.

Sorry.
 
so does X = 120 grams?
 
that is the correct answer.
 

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