A uniform rectangular thin sheet $ABCD$ of mass $M$ has length $a$ and breadth $b$, as shown in the figure. If the shaded portion $HBGO$ is cut off, the coordinates of the centre of mass of the remaining portion will be
$\left( {\frac{{5a}}{3},\frac{{5b}}{3}} \right)$
$\left( {\frac{{2a}}{3},\frac{{2b}}{3}} \right)$
$\left( {\frac{{3a}}{4},\frac{{3b}}{4}} \right)$
$\left( {\frac{{5a}}{12},\frac{{5b}}{12}} \right)$
A rigid body can be hinged about any point on the $x$ -axis. When it is hinged such that the hinge is at $x$, the moment of inertia is given by $I = 2x^2 - 12x + 27$ The $x$ -coordinate of centre of mass is
A square shaped hole of side $l=\frac{a}{2}$ is carved out at a distance $d =\frac{ a }{2}$ from the centre $'O'$ of a uniform circular disk of radius $a$. If the distance of the centre of mass of the remaining portion from $O$ is $-\frac{a}{X},$ value of $X$ (to the nearest integer) is.......
A thin uniform wire is bent to form the two equal sides $AB$ and $AC$ of triangle $ABC$, where $AB = AC = 5\,cm.$ The third side $BC$, of length $6\,cm,$ is made from uniform wire of twice the density of the first. The distance of centre of mass from $A$ is
A circular disc of radius $R$ is removed from a bigger circular disc of radius $2R$ such that the circumferences of the discs coincide. The centre of mass of the new disc is $\frac{\alpha}{R}$ form the centre of the bigger disc. The value of a is $\alpha $ is
$A$ man weighing $80\, kg$ is standing at the centre of a flat boat and he is $20\, m$ from the shore. He walks $8\, m$ on the boat towards the shore and then halts. The boat weight $200\, kg$. ........ $m$ far is he from the shore at the end of this time.