Suppose that we wish to find the "net force" on an automobile, in order to apply Newton's law of motion to the motion of the automobile. As part of the net force, do we need to include "internal frictional forces" due to internal gears, bearings, etc.?
A) Yes, because every internal and external force must be included.
B) No, because only external forces need to be included.
C) Yes, because of Newton's law of force pairs.
D) Yes, because these forces dissipate some of the car's energy.
E) No, because only the drive force needs to be included.

Question

Quizplus · Accepted Answer

Internal frictional forces do not contribute to the net force on the automobile because they are internal to the system.

Suppose That We Wish to Find the "Net Force" on an Automobile