As shown in the figure rod of mass `m` and length `l` is hinged at `O` at one end and free to rotate in vertical plane. A force `F` of magnitude `mg` is applied on another end of rod which always act perpendicular to be rod. Force is start acting at time `t=0` (as shown). Find vertical component of normal reaction acting on rod when rod become horizontal for 3rd time (given `m=2 kg, l=1m, g=10m//s^(2)`)

Options

A. The number of next to next neighbours are 24 at a distance of `sqrt(6)a`
B. The packing fraction of cubic unit cell is 0.74
C. The edge fraction unoccupied by the particle is 0.293
D. The volume fraction occupied by the particle is 0.731 if all octahedral voids occupied by the particles with idea radius particles in unit cell.