# Center of Mass

## Homework Statement

Determine the position of the center of mass of a whole leg (a) when stretched out, and (b) when bent at 90°. Assume the person is 1.70 m tall.

## Homework Equations ## The Attempt at a Solution

This is where I'm stuck...what's the mass? I doubt I can just use variable m because the mass is different parts of the leg. Also, when the problem says that the person is 1.7 m tall, should I use that for leg length and assume they meant leg length instead of height?

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Is that all the information you are given? No diagram or anything? I think I would be led to believe that the point about the person being "1.70m tall" is some sort of red herring.

Yes, sadly that's all the information I'm given, not even a diagram.

gneill
Mentor
There's probably some standard body part model used in kinesiology and the like. No doubt there are mass models for sections of each limb, and I wouldn't be surprised if there's some sort of height index to scale the model.

Where does this problem come from?

It's from my physics homework .

I would guess that your professor assigned you this piece of work but forgot to reference where you could find the question in your textbook, maybe you'll find more information there 