Motion of centre of mass (F_ext = M a_cm)

jee-mainjee-advancedneet-ug

F_ext = M a_cm

What each symbol means

SymbolWhat it stands for
MTotal mass of the system (kg)
a_cmAcceleration of centre of mass (m/s²)
F_extVector sum of external forces on the system (N)

When to use this

Valid for any system of particles; internal forces cancel in pairs (Newton III).