State one difference between circular motion and rotaional motion.
Answers
Answer:
The main difference between these types of motion is that circular motion is a special case of rotational motion, where the distance between the body's center of mass and the axis of rotation remains fixed. Rotational motion is based around the idea of rotation of a body about its center of mass.
Maybe a better distinction to make would be between rotational motion and orbital motion. Even in that more generalized case (orbital could be something other than circular), the properties used to describe and analyze the motions are the same: axis of motion, angular momentum, moment of inertia, kinetic energy, torque, etc.
There is not a bold line of difference between the two, but generally, rotational motion refers to objects which are extended (not points) and spin about an axis which either within the material of the object or is not farther from the center of mass than the farthest dimension of the object.
Orbital (or "circular") refers to the motion of an object, which may or may not be spinning around an internal axis, around some point far from its center of mass and either repeats a path or nearly repeats a path (e.g., Mercury). More generally, the path doesn't even need to repeat because there are open orbital paths which astronomical objects routinely take.
One could say that rotational motion of a solid object is the orbital motion of thousands of particles, all moving about the same axis with the same angular frequency.
Answer:
For something to be 'circular motion,' it just has to move in a circle. For example, a toy train on a circular track has circular motion. For something to have 'rotational motion,' it has to actually have something that it's rotating around (called an axis).