Q: At the beginning of the lecture today when explaining a fixed pulley, you mentioned there being a connection between circular motion and rotation. I am a bit confused about what exactly the relationships are between them and was wondering if you could provide me a bit more clarity about it.
A: For a rotating extended object, the whole body is in a Rotation about an axis, while every point on the body is in a Circular Motion (see picture).
Any two points on the rotating object at different distances (r) from the axis of rotation have equal angular speeds/velocities, but different linear speeds.
Linear speed (v) and angular speed (ω) have the relationship: v = ωr.
