Particles of masses $m, 2m, 3m, ...... nm$ $grams$ are placed on the same line at distances $l, 2l, 3l,...., nl\, cm$ from a fixed point. The distance of the centre of mass of the particles from the fixed point (in centimetres) is
$\frac{{\left( {2n + 1} \right)l}}{3}$
$\frac{l}{{n + 1}}$
$\frac{{n\left( {{n^2} + 1} \right)l}}{2}$
$\frac{{2l}}{{n\left( {{n^2} + 1} \right)}}$
Three masses of $2\,kg$, $4\, kg$ and $4\, kg$ are placed at the three points $(1, 0, 0)$ $(1, 1, 0)$ and $(0, 1, 0)$ respectively. The position vector of its center of mass is
A tube of length $L$ is filled completely with an incompressible liquid of mass $M$ and closed at both the ends. The tube is then rotated in a horizontal plane about one of its end with a uniform angular velocity $\omega$. The force exerted by the liquid at the other end is
Two particles $A$ and $B$ initially at rest move towards each other under a mutual force of attraction. At the instant when velocity of $A$ is $v$ and that of $B$ is $2v$, the velocity of centre of mass of the system :
A carpenter has constructed a toy as shown in the adjoining figure. If the density of the material of the sphere is $12$ $times$ that of the cone, the position of the centre of mass of the toy is given by
Radius of gyration of a body depends on