Why are the direction of angular velocity and acceleration on the rotating shaft in circular motion This is the problem I met in college physics It's really on the axis, not pointing to it

Why are the direction of angular velocity and acceleration on the rotating shaft in circular motion This is the problem I met in college physics It's really on the axis, not pointing to it

The definition of acceleration is LIM (t → 0) △ V / △ T, that is, the derivative of velocity with respect to time. You can try to make a particle turn a very small angle in circular motion and calculate) △ V / △ T. in this way, you can calculate the value of acceleration. The direction of acceleration can be described as follows: if there is an acceleration along the tangent direction, then the velocity