Two particle of masses $1\,kg$ and $3\,kg$ have position vector $2\hat i + 3\hat j + 4\hat k$ and $ - 2\hat i + 3\hat j - 4\hat k$ respectively. The centre of mass has a position vector

The centre of mass of a body

A rod of length is $3 \;m$ and its mass acting per unit length is directly proportional to distance $x$ from one of its end then its centre of gravity from that end will be at

What is centre of mass ?

$A$ small ball $B$ of mass $m$ is suspended with light inelastic string of length $L$ from $a$ block $A$ of same mass $m$ which can move on smooth horizontal surface as shown in the figure. The ball is displaced by angle $\theta$ from equilibrium position & then released. The displacement of centre of mass of $A+ B$ system till the string becomes vertical is

Infinite rods of uniform mass density and length $L, L/2, L/4....$ are placed one upon another upto infinite as shown in figure. Find the $x-$ coordinate of centre of mass