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1. Ok so I have a thin non uniform rod, and i'm given the length of the rod, and the mass density as a function of x... x being how far from the bottom of the rod you go. Then it's asking me to find the total mass =/

So far I've got this:

(where rho of x is the mass density function)
Thennn, total mass is if you integrate it from i = 1 to i = L? I think?
But how do I integrate the RHS please, if thats right?

Does it just become the integral of (density function)?

Also, how can I find the centre of mass because atm I've ended up with a cubic, with decimal coefficients - not so easy to solve!
3. (Original post by TheRandomer)

Also, how can I find the centre of mass because atm I've ended up with a cubic, with decimal coefficients - not so easy to solve!
im not too sure about the mechanics of it - this seems at least M2 standard and i've only done M1 and haven't had much chance to venture into M2. but if you can't solve it with the decimal coefficients, can't you multiply them away. im assuming you have a cubic equal to zero? then multiplying away the decimal coefficients should remove that problem? perhaps try plotting the graph, to see where it intersects the x-axis (where f(x)=0, and f(x) = your cubic equation)

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Updated: November 9, 2008
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