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scorpius1782
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Homework Statement
This is similar to another problem I've posted but is supposedly more difficult.
Cylinder with dimensions radius=R and height=2L has density of ##\rho=\rho_o(1+cos(\phi))##
Find the position of the cylinders center of mass.
Homework Equations
##r_{cm}=\frac{\int\vec{r}dm}{\int dm}##
The Attempt at a Solution
I have Mass##=\int_0^R\int_0^2L\int_0^{2\pi}\rho_o(1+cos(\phi))s ds d \phi dz##
So, ##2L\frac{R^2}{2}\int_0^{2\pi}\rho_o(1+cos(\phi))d \phi##
=##2L\frac{R^2}{2}(\rho_o2\pi+\int_0^{2\pi}\rho_ocos(\phi))d \phi##
where ##\int_0^{2\pi}\rho_ocos(\phi)=0##
so M=##2L\frac{R^2}{2}(\rho_o2\pi)=2LR^2\rho_o\pi##For the positions then:
##\int_0^R\int_0^{2L}\int_0^{2\pi}\rho_o(1+cos(\phi))s(s) ds d \phi dz## for ##\hat{s}##
##\int_0^R\int_0^{2L}\int_0^{2\pi}\rho_o(1+cos(\phi))s(\phi) ds d \phi dz## for ##\hat{\phi}##
##\int_0^R\int_0^{2L}\int_0^{2\pi}\rho_o(1+cos(\phi))s(z) ds d \phi dz## for ##\hat{z}##
Then I should just divide each integral by the mass from before. Is this the correct method? It seems a little too straightforward for being "more difficult."Thanks for the help.
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