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johnnyb
Mar31-05, 12:23 AM
Any help would be great

Show that the centre of the mass of a uniform circular disk of radius, R, is at a point (4/3pi)R from the centre of the circle.

whozum
Mar31-05, 12:30 AM
The center of mass of a uniform disk is the center.

johnnyb
Mar31-05, 12:34 AM
Yeh thats what I'm having a problem with, seems like a stupid question, but still have to prove that it is (4/3pi)R

neutrino
Mar31-05, 12:41 AM
Any help would be great

Show that the centre of the mass of a uniform circular disk of radius, R, is at a point (4/3pi)R from the centre of the circle.
Where is the circle located?

johnnyb
Mar31-05, 12:50 AM
Thats all the information that is given

Show that the centre of the mass of a uniform circular disk of radius, R, is at a point (4/3pi)R from the centre of the circle

Altho below it does say...

X co-ord is obvious..to find y co-ord integrate using

Mr = \intrdm

and transform y into an appropriate co-ord system

johnnyb
Mar31-05, 01:14 AM
any ideas?

whozum
Mar31-05, 01:20 AM
that doesnt make sense. i dont know what to tell you.

johnnyb
Mar31-05, 02:12 AM
Don't worry bout it, i'll keep trying

dextercioby
Mar31-05, 04:10 AM
In the way it's formulated,the problem's incorrect.It would have made it interesting,if it had mentioned about a half of the initial disk.

Daniel.

DaveC426913
Mar31-05, 09:57 AM
This is nonsense.

The centre of mass of a circular disc with radius 1 unit is going to be 4.19 units from the centre of the disc?


I'd like to see that!
(I could make an end table for my desk that floats in mid-air!)