A piece of paper (shown in figure 1) is in form of a square. Two corners of this square are folded to make it appear like figure2. Both corners are put together at centre of square 'O'. If O is taken to be (0, 0), the centre of mass of new system will be at

Options

A. `(- (a)/(8),0)`
B. `(-(a)/(6),0)`
C. `((a)/(12),0)`
D. `(-(a)/(12), 0)`

Answer

D

Explanation

`bar(x) = (M_(1)x_(1) + M_(2)x_(2))/(M_(1) + M_(2)) = ((M)/(2)(-(a)/(2)) + (M)/(2) ((a)/(3)))/(M) = -(a)/(12)`