## College Physics (4th Edition)

The tangential acceleration is $~g~sin~\theta$
The tension in the string is perpendicular to the direction of motion, so it does not affect the tangential acceleration. The component of the gravitational force directed parallel to the direction of motion provides the force for the tangential acceleration: $mg~sin~\theta = m~a_t$ $a_t = g~sin~\theta$ The tangential acceleration is $~g~sin~\theta$.