The speed of circular motion can be measured by the ratio of the length of the arc that the object passes through to the time taken. If an object moves from M to N, it passes through point A at a certain time t. In order to describe the speed of movement when passing near point A, we can start from this moment and take a very short period of time △t. During this period of time, the object moves from A to B, and the arc length passed is △L. The ratio △l/△t reflects the speed of the object's movement, which is called linear velocity, represented by v, that is, v=△L/△t. Linear velocity can also be divided into average value and instantaneous value. If the time interval taken is very small, the instantaneous linear velocity is obtained.

Note that when △t is small enough, arc AB becomes almost a straight line, and the length of arc AB is almost the same as the length of line segment AB. At this time, △l is the displacement of the object from A to B. Therefore, v here is actually the instantaneous velocity in linear motion, but now it is used to describe circular motion.

Linear velocity is a vector with magnitude and direction. For an object doing circular motion, the direction of its linear velocity changes all the time and always points in the tangent direction of that point.

Circular speed calculator:

Linear speed: V = 2*PI*r / T

here:

r = radius

T = time period