A square plate of edge d and a circular disc of diameter d are placed touching each other at the midpoint of an edge of the plate as shown in figure (9-Q2). Locate the center of mass of the combination, assuming same mass per unit area for the two plates.

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We are given that the mass per unit area for the two plates is same. Let it be ‘m’


Mass of the circular disc, m1 = mϖ(d/2)2


Mass of the square plate, m2 = md2


Assuming the origin to be at centre of the circular disc,


Position of the centre of mass of the circular disc (x1, y1) = (0,0)


Position of the centre of mass of the square plate (x2, y2) = (d,0)






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