acceleration, : final acceleration, : initial velocity, : final velocity, : initial position, : final position, : time between initial and final states. The dimensions of crackle are LT−5. In SI units, this is m/s5, and in CGS units, 100 gal per cubed second. The sixth derivative of the position vector with respect to time is sometimes referred to as pop. It is the rate of change of crackle with respect to time. Pop is defined by any of the following equivalent expressions: The following equations are used for constant pop: where : constant pop, : initial crackle, : final crackle, : initial snap, : final snap, : initial jerk, : final jerk, : initial acceleration, : final acceleration, : initial velocity, : final velocity, : initial position, : final position, : time between initial and final states. The dimensions of pop are LT−6. In SI units, this is m/s6, and in CGS units, 100 gal per quartic second. References External links Acceleration Kinematic properties Time in physics Vector physical quantities