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# central mass watch

Find the center of mass of a solid with constant density (rho), bounded by x=y^2, x=z, z=0, x=1.

I had a paraboloid that is inclined with the z-axis.

Then what should i do next? how can i get the mass? I'm confused.
2. Right, it's ages since I did any center of mass stuff, and I can't remember the details, but the following things might help you get started.

1) Draw a picture. I did 4 before I was happy with it

2) If you want the total mass, you know the density, and you know the boundaries of the shape, and I'm sure you know multiple integration I have a 3D solid, so it definitely has positive mass (provided the density is >0 )

3) Working out the y bit of the center of mass should be fairly straightforward if you're happy with the shape and its density.

Does that give you any sense of direction with the problem?
3. (Original post by ImperceptibleNinja)
Right, it's ages since I did any center of mass stuff, and I can't remember the details, but the following things might help you get started.

1) Draw a picture. I did 4 before I was happy with it

2) If you want the total mass, you know the density, and you know the boundaries of the shape, and I'm sure you know multiple integration I have a 3D solid, so it definitely has positive mass (provided the density is >0 )

3) Working out the y bit of the center of mass should be fairly straightforward if you're happy with the shape and its density.

Does that give you any sense of direction with the problem?
Yeah yeah. My problem is, how will I start the equation of multiple integration? lol

Y is the best starting variable?
4. Is this any help?

5. Thanks. I can imagine the graph. Can you give any starting equation?
6. (Original post by gel)
Thanks. I can imagine the graph. Can you give any starting equation?
http://tutorial.math.lamar.edu/Class...terOfMass.aspx
7. (Original post by steve2005)
http://tutorial.math.lamar.edu/Class...terOfMass.aspx
Thanks. Big help.

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