Rotational velocity

einsteinian77

How could i calculate the velocity of an object rotated around a fixed point such as a hand on a clock. It seems as though each section of the hand would have a different velocity, the end part being the fastest while the beginning part being the slowest if not moving at all. Im guessing the velocity would be expressed in frequency somehow.

Related Other Physics Topics News on Phys.org

arcnets

Originally posted by einsteinian77
Im guessing the velocity would be expressed in frequency somehow.
That's correct, einsteinian77. Since the rotational velocity v increases proportional with radius r (distance from center), you define the angular velocity
[nu] = v/r.
This is the same for all points. The unit is 1/s. You could also say it's radians per second, since by integrating you get the angle:
[alpha] = a/r
where a is the arc length, and [alpha] is measured in radians.

Last edited:

Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving