Tangential speed

[1] A point on the outside edge of a merry-go-round or turntable travels a greater distance in one complete rotation than a point nearer the center.

For circular motion, the terms linear speed and tangential speed are used interchangeably, and is measured in SI units as meters per second (m/s).

All parts of a rigid merry-go-round or turntable turn about the axis of rotation in the same amount of time.

(Angular speed and angular velocity are related to the rotational speed and velocity by a factor of 2π, the number of radians turned in a full rotation.)

Towards the edge of the platform the tangential speed increases proportional to the distance from the axis.

One moves faster if the rate of rotation increases (a larger value for ω), and one also moves faster if movement farther from the axis occurs (a larger value for r).

When proper units are used for tangential speed v, rotational speed ω, and radial distance r, the direct proportion of v to both r and ω becomes the exact equation

Thus, tangential speed will be directly proportional to r when all parts of a system simultaneously have the same ω, as for a wheel, disk, or rigid wand.