Find the centre of mass of a uniform plate having semicircular inner and outer boundaries of radii R1 and R2 (figure 9-E5).


m5.png


The x coordinate of centre of mass will be 0.


Let the mass per unit of the plate be m.


Mass of the semi-circular plate having radius R2 = m2 = ϖ(R2)2m


Mass of the semi-circular plate having radius R1 = m1 = ϖ(R1)2m


y-coordinate of centre of mass of semi-circular plate having radius R2 = y2 = 4R2/3ϖ


y-coordinate of centre of mass of semi-circular plate having radius R1 = y1 = 4R1/3ϖ








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