Question

A system of particles in motion has mass center G as shown in the figure. The particle i has mass m_i and its position with respect to a fixed point O is given by the position vector r_i. The position of the particle with respect to G is given by the vector $\rho$_i. The time rate of change of the angular momentum of the system of particles about G is (The quantity  $\ddot{\rho _{i}}$ indicates second derivative of r_I with respect to time and likewise for r_i).

      (a) $\sum ir_{i}$$\times m_{i}\ddot{\rho } _{i}$                                                 (b) $\sum i \rho _{i} \times m_{i} \ddot{r}_{i}$

 

    (c)$\sum ir_{i}\times m_{i} \ddot{r}_{i}$                                                    (d) $\sum i\rho _{i}\times m_{i} \ddot{\rho } _{i}$

Answer 1

Given a system of particles in motion