Obtain Newton.s second law for system of particle and write it.

Explanation

Linear momentum of system of particle
`vecp=mvecv" "...(1)`
Taking differention on both side with time
`(dvecp)/(dt)=M(dvecv)/(dt)` (where M = constant)
`therefore (dvecp)/(dt)=MvecA" "...(2)`
but `MvecA=vec(F)_(ext" "…(3)`
From equation (2) and (3),
`(dvecp)/(dt)=vecF_(ext)" "...(4)` is a Newton.s second law for the system of particles.
The external force acting on a system is equal to rate of change of total linear momentum of the system... This is Newton.s second law for a system.