Question

Length of a minute hand of a clock is 4.5cm. Find average velocity of tip of the minute between 6A.M. to 6.30 A.M. & 6A.M. to 6.30 P.M.

Answer 1

1. R = the radius = 4.5 cm;
2. C = the circumference = 2 * $\pi$ * R = 28.27433388 cm;
3. V = the velocity = C / T ...

...about 28.27 cm per hour, or...
...roughly 4.71 mm per minute, or...
...around 0.08 mm per second.

As velocity does not depend on the time periods presented, they do not play any role in the calculations.