Question

How to find direction acceleration in a swinging arm?

Answer 1

Magnitude can change and its direction can change. Either change gives rise to an acceleration. For circular motion at constant speed, the velocity is always tangential to the circular path, and therefore its direction is continuously changing even though its magnitude is constant. Therefore, the object has an acceleration. It can be shown that the magnitude of the acceleration ac for uniform circular motion with speed v in a path of radius R