Which of the following is classified as a scalar quantity?

A scalar quantity is one that is fully described by a magnitude alone and does not have a direction. Power, which is classified as a scalar quantity, measures the rate at which work is done or energy is transferred. It is expressed in watts (joules per second) and involves only the numerical value, independent of any directional component.

In contrast, velocity and acceleration are vector quantities because they have both magnitude and direction. Velocity specifies how fast something is moving and in what direction, while acceleration denotes the rate of change of velocity with respect to time, also needing directional information. Force, similarly, cannot be fully described without indicating the direction in which it acts, as it is defined as mass times acceleration (F = ma), giving it both a magnitude and a direction. Therefore, only power fits the definition of a scalar quantity among the provided choices.