Non-uniform circular motion
So far in this chapter we've dealt only with uniform circular motion. How do we handle rotations when the angular velocity is not constant? In this last section, we'll begin to look at this problem and illustrate it with an example. A fuller treatment of non-uniform rotation will involve delving into concepts such as angular momentum and torque. For that, you'll have to await Chapter 13.
Tangential force and acceleration
The underlying difference between uniform and non-uniform circular motion is that in the former, centripetal force is the only force, whereas in the latter there is a tangential as well as a centripetal force (see Figure 9-10). Tangential literally means “along a tangent” to the circle. The centripetal ...