2011-03-19, 08:56 PM
The velocity vector is not constant. The magnitude of velocity is constant.
Given that distinction, then yes, tangential acceleration is the derivative of speed, so if acceleration is perpendicular => there is no tangential acceleration => speed is constant.
Given that distinction, then yes, tangential acceleration is the derivative of speed, so if acceleration is perpendicular => there is no tangential acceleration => speed is constant.