Question

Question: If an object is in equilibrium, which of the following statements is not true? (a) The speed of the object remains constant. (b) The acceleration of the object is zero. (c) The net force acting on the object is zero. (d) The object must be at rest. (e) There are at least two forces acting on the object.

Short answer

The correct option is (d): The object must be at rest.

Step-by-step solution

Definition of an equilibrium system

The system is in equilibrium when the state of the motion and internal energy do not change with respect to time.

The object is said to be in equilibrium if it does not experience linear acceleration and angular acceleration until an external force disturbs the object.

Determine the correct statement for the object in equilibrium

In the state of equilibrium, the net force on the object must be zero, resulting in zero acceleration. Therefore, the velocity of the object must be constant. The speed of the object should be constant but may have some value. Therefore, the object must not be at rest.

Hence, the object must not be at rest.