Four homogeneous brick, each of length L=4m, are arranged as shown in the figure. Each brick is displaced with respect to one in contact by L8. Find the x− coordinate of centre of mass relative to origin O.
The correct option is D2.75m length of each brick, L=4m, Let the mass of each brick be mkg.
⇒Initially all four bricks have their COM at L2=2m from the x−axis.
After displacing the bricks, coordinates relative to origin O : x− coordinate of COM of brick (1)⇒x1=L2 x− coordinate of COM of brick (2)⇒x2=L2+L8=58L x− coordinate of COM of brick (3)⇒x3=L2+L8+L8=68L x− coordinate of COM of brick (4)⇒x4=L2+L8+L8+L8+78L Replacing the bricks by point masses placed at their COM , the x− coordinate of COM of system: