find center of mass of a wire bend as a semi circlE

i got it it will be at mid point of perpendicular line drawn frm centre to of the circle..

@ravi00 can u prove ur above assertion?

see now...join  the opp points of the semicircle and itz midpoint will be centr of massof 2 points that is centre of circle.so considering all points of semicircle...it will be a straight line of centr of masses ..so considering half of it will be its centre mass of semicircle

RATE ME IF I SATISFY YOUR QUE

ya i knew u were wrong

i just wanted u to realize that things aren't that ob as they seem

ok so can u think of a valid approach?

i can do this but since u attempte dthis first i want to see u thru this problem

It is obviously on the line of symmetry .

Let it is at a distance z from the midpoint of the base .

so z= int ( x dm ) / int dm

= 2r int ( cos @ d@)/pi  with the integral extends fro 0 to pi/2

= 2r/pi