Which of the following is not an example of a dynamic body?

A dynamic body is defined as one that is in motion and affected by forces. The choices that involve acceleration or deceleration indicate that these bodies are changing their velocity, thus demonstrating dynamic behavior. In contrast, a body moving at a uniform velocity along a straight line is not considered dynamic because it is in a steady state of motion, meaning there is no net force acting on it, and its speed and direction remain constant. Therefore, it does not involve acceleration or changing conditions.

This characteristic of uniform motion is essential in distinguishing between dynamic and static conditions. Dynamic bodies are always transitioning from one state to another, while a body moving at a uniform velocity is stable in its current motion, indicating a lack of dynamic change. Thus, the choice pertaining to uniform motion aligns with the definition of being not dynamic, as it implies equilibrium rather than change.