Angular acceleration Angular acceleration is the rate of change of angular velocity over time. Measurement of the change made in the rate of change of an angle that a spinning object undergoes per unit time. It is a vector quantity. Also called Rotational acceleration. In SI units, it is measured in radians per second squared (rad/s^2), and is usually denoted by the Greek letter alpha. Space and Time QUDT http://qudt.org/vocab/quantity#AngularAcceleration ODM2 Units Type Controlled Vocabulary ODM2 Working Group A vocabulary for describing the type of the Unit or the more general quantity that the Unit represents.