Activity: Circular motion
Circular motion, like linear motion, has a number of quantities to be defined, described and derived, including centripetal acceleration. Here you will also understand that a constant force perpendicular to direction of motion results in a circular path and become able to solve problems involving motion in a circle.
Need to know
In this example we will consider the well known example of the motion of a ball moving in a circle on the end of a string, however to make the forces simpler we will consider this in space.
To describe this motion we will define some new terms:
Time period (T) = time for one complete circle - unit: s
Frequency (f) = number of complete circles per second (1/T) - unit: Hz
Angular displacement (θ) = angle swept out in radians - unit: rad
Angular velocity (ω) = angle swept out per unit time - unit: rad s-1