If the total momentum of a system is changing:
A)particles of the system must be exerting forces on each other
B)the system must be under the influence of gravity
C)the center of mass must have constant velocity
D)a net external force must be acting on the system
E)none of the above

Question

Quizplus · Accepted Answer

According to Newton's Second Law, the rate of change of momentum of a system is equal to the net external force acting on the system. Therefore, if the total momentum of a system is changing, there must be a net external force acting on the system.

If the Total Momentum of a System Is Changing