Center of mass with one object moving

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DrummingAtom
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Homework Statement



Two objects are on a stick where one is stuck in place and the other one can slide. Both objects have the same mass and the stick has negligible mass.

Homework Equations



[tex]COM = \frac{m_1 x_1 + m_2x_2}{m_1+m_2}[/tex]
[tex]v_1 = t[/tex]

The Attempt at a Solution



[tex]COM = \frac{m_1 \int v_1 + m_2x_2}{m_1+m_2}[/tex]

Would this be correct assuming that the starting point for measuring x1 and x2 would be the left side? Thanks
 

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I would be a little careful here. You need to know the initial position of the moving mass:
[tex]\frac{m_1\left (\int v_1(t) \,dt +x_1(0) \right ) + m_2x_2}{m_1+m_2}[/tex]
where x_1(t) is a function of time and x_1(0) is the constant of integration.
 
Last edited:
RoshanBBQ said:
I would be a little careful here. You need to know the initial position of the moving mass:
[tex]\frac{m_1\left (\int v_1(t) \,dt +x_1(0) \right ) + m_2x_2}{m_1+m_2}[/tex]
where x_1(t) is a function of time and x_1(0) is the constant of integration.

Thanks for responding. Ahh yes good point. Adding your part, would that be correct? I just made up the problem which is why I'm a little unsure of the conceptual part.
 
DrummingAtom said:
Thanks for responding. Ahh yes good point. Adding your part, would that be correct? I just made up the problem which is why I'm a little unsure of the conceptual part.

I believe it is all right. The equation gives the center of mass as a function of time.
 
Ok cool. Thanks for your help. By the way.. Roshan from DotA? :wink:
 
DrummingAtom said:
Ok cool. Thanks for your help. By the way.. Roshan from DotA? :wink:

Yes. DotA 2 now.