Question

In mechanics, the term equilibrium implies that:

A) The body of concern must be at rest
B) The body of concern is in constant motion
C) The body of concern is either at rest or moving with constant velocity
D) All forces acting on the body are not at rest

Answer 1

Equilibrium in mechanics refers to a state where a body is either at rest or moving with constant velocity due to the absence of net external forces causing acceleration, in accordance with Newton's First Law of Motion.

Step-by-step explanation:

In mechanics, the term equilibrium implies that the body of concern is either at rest or moving with constant velocity. This can be understood in the light of Newton's First Law of Motion, which states that a body at rest remains at rest, or if in motion, continues to move at a constant velocity unless acted upon by a net external force. Therefore, equilibrium does not necessarily mean that a body must be stationary.

A body is in static equilibrium when it is at rest in a given frame of reference. On the other hand, a body is in dynamic equilibrium when it is moving with constant linear and angular velocities. In both cases, there are no net external forces causing any acceleration, and this is a condition of equilibrium.