Cortana is an intelligent personal assistant created by Microsoft for Windows Phone 8.1 and Windows 10 (where it now supersedes Bing Mobile), Microsoft Band, Windows 10, and coming to iOS, Android, and the Xbox One.
a force which is the result of two or more forces acting conjointly, or a motion which is the result of two or more motions combined. See Composition of forces, under Composition.
Definition of impetus. 1a (1) : a driving force : impulse (2) : incentive, stimulusb : stimulation or encouragement resulting in increased activity. 2 : the property possessed by a moving body in virtue of its mass and its motion âused of bodies moving suddenly or violently to indicate the origin and intensity of the motion.