Question

A system can have a nonzero velocity while the net external force on it is zero. Describe such a situation.

Short answer

The situation where a system moves with the nonzero velocity with zero net external force is pushing an object across the floor at constant velocity.

Step-by-step solution

Concept of Newton’s second law of motion

Newton’s second law of motion states that the acceleration of a system is directly proportional to the net external force acting on the system and is inversely proportional to the mass of the system. Mathematically,

$F_{net}=ma$

Here $F_{net}$is the net force,localid="1654167109493" ${}^m$is the mass, andlocalid="1654167042552" ${}^a$is the acceleration.

Explanation for a system with zero net external force having a nonzero velocity

The situation where a system moves with the nonzero velocity with zero net external force is pushing an object across the floor at constant velocity.

When the net external force acting on a body is zero, the body does not experience any acceleration. So, when a body has a non-zero velocity, and a net external force of zero, this clearly suggests that the body is moving at a constant velocity and without accelerating.