Find coordinates of mass center of a uniform semicircular plate of radius r placed symmetric to the y-axis of a Cartesian coordinate system, with centre at origin.

Explanation

The y-axis is the line of symmetry, therefore mass center of the plate lies on it making x-cordinate zero. Distance OC of mass center from center is given by the result obtained in example 7. Making use of this result, we have
`OC = (r2r sin theta)/(3 theta)rarr y_(c ) = (2r sin (pi//2))/(3pi//2) = (4r)/(3r)`