center of mass
posted by lou on .
3 point mass of 4g placed at x=1,3,6. where should a point fourth mass of 4 gm be placed to make the center of the mass at the orgin?
this what i got : 24+4+12+4x/16=8+4x/16. this what i did but i didn't get the right answer(which is 2) can someone tell me what is the problem

to find the center of mass, you add up all of the xpoints * all of their corresponding masses. (e.g. sum x*m)
and you divide it by the sum of all of the masses (e.g. sum m)
therefore (sum x*m)/(sum m).
you are looking for where to place x to make the center of mass at the origin.
so (1*4)+(3*4)+(6*4)+(x*4) = 0
solve for x.
8 = (x*4)
x = 2
TahDah!!