Final answer:
VT2 stands for Velocity at Threshold in an incremental test protocol, which is a concept in physics related to motion where acceleration is the rate of change of velocity.
Step-by-step explanation:
VT2 represents Velocity at Threshold during the incremental test protocol. The rate of change of velocity is called acceleration. In physics, when working with motion, these concepts are significant. For example, the area under a velocity-time graph represents displacement, while the gradient of a velocity-time graph indicates the acceleration. Similarly, the area under an acceleration-time graph gives the change in velocity, and the gradient of a position-time graph represents velocity. When analyzing motion, it's common to examine graphs showing acceleration versus time, velocity versus time, and displacement versus time to understand fully an object's movement.