Speed of light and rotations per minute is very small objects

Question

I have an object/sphere that is 4 millionth of a meter in diameter and is rotating per minute at 600 million rpm. My question is how fast is it moving with respect to the speed of light?

Answer 1

Juan

        The axis of rotation is through the poles an the speed of a point on the equator is π*D*f where D=the diameter and f=600*10⁶/60 is the frequency of rotation in Hz (sec^-1) This will give the speed of a point on the equator. Then all you have  to do is divide that number by c, the speed if light (approx 3*10⁸ m/sec).

 

The ratio is 4*600*3.14159/(60*300,000,000)=4.18*10^-7

 

Hope this helps

 

Jim