Jerk (Physics)

Jerk, also called jolt, is the rate of change of an objects acceleration over time in classical mechanics. It is a vector quantity, defined as the first time derivative of acceleration, the second time derivative of velocity, and the third time derivative of position, so jerk equals da/dt equals d2v/dt2 equals d3r/dt3. In SI units jerk is measured in metres per second cubed. Because it measures how abruptly acceleration itself changes, jerk is a practical consideration in fields such as vehicle ride comfort and elevator engineering, where a sudden change in acceleration is felt as an uncomfortable jolt.