Angular velocity determines how much time it will take to rotate an object. Or rather how many radians it will rotate in one second. To easily determine which of the axes rotates (when the angular velocity is represented by a vector), take your right hand and curl your fingers, with your thumb pointing up. In this example, your thumb represents the Y-axis, and the angular velocity is represented by your fingers curling counter-clockwise. If the Y-axis value is positive, then the counter-clockwise rotation is positive. A negative value would rotate the object clockwise.