# Confused about Center of mass

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#### deleted647690

Could someone explain how center of mass affects this problem? I initially thought the MA was 2 because I didn't realize the COM was different from the fulcrum. Still, wouldn't the center of mass be 0.5 units away from the applied force downward and 1.5 units from the applied force upward? Meaning that the MA is actually greater than 2?

Sorry that the image is rotated.....

#### babyoreo

##### Full Member
7+ Year Member
Where did you find this question? It seems poorly written. Where is the center of mass? What is W? What is F? Which is the input force, which is the output force? The MA of a lever depends on the relative distances of these from the fulcrum.

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D

#### deleted647690

Where did you find this question? It seems poorly written. Where is the center of mass? What is W? What is F? Which is the input force, which is the output force? The MA of a lever depends on the relative distances of these from the fulcrum.

Sorry; this was part of a passage which I did not include. It was from TBR.

Dang, I don't have the book with me right now for reference, but the passage basically just explains that mechanical advantage is the ratio of the force applied to the weight you are trying to lift, or the ratio of the distance the weight you are trying to lift is from the fulcrum compared to the distance of the force applied.

The confusion for me was that the fulcrum was not at the center of mass, and that means that the weight of the beam somehow influences the torque.

It didn't give actual numbers for F and W, because you were supposed to just figure it out based on the ratio of distances between the two.

Hopefully I'm not forgetting something that was included in the passage. I'll take a look when I get the book back.