Q. If the resultant of all the external forces acting on a system of particles is zero, then from an inertial frame, one can surely say that
A) Liner momentum of the system does not change in time
B) Kinetic energy of the system does not change in time
C) Angular momentum of the system does not change in time
D) Potential energy of the system does not change in time
Explanation
(a) On the system of particle if,
$\sum_{}^{}{\mathbf{F}_{ext} = 0}$
$then\ \ \mathbf{P}_{system} = constant$
No other conclusions can be drawn.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.