Pulley Revolutions

## Question:

SORRY MY ENGLISH. I"M SENDING YOU THIS QUESTION FOR HAVING
AN AUTHORITY ANSWER FOR A PRACTICE MATTER. IF I HAVE A SYSTEM
CONSISTENT THREE PULLEYS : A,B AND C, AND FOR A AND B EXISTS THE
SAME RATIO OR DIAMETER DIMENSIONS, I THINK THEY"LL TAKE THE
SAME NUMBER OF ROUNDS CONECTED BY A BAND. BUT IN THE SYSTEM, C
PULLEY HAS A DIAMETER ABOUT HALF OF A OR B. DOES C TAKES THE SAME
NUMBER OF ROUNDS THAN A OR B PULLEYS? DOES EXISTS SOME
PROPORCIONAL KEY TO KNOW HOW MANY ROUNDS ITS TAKE? NOTE THAT THE
THREE PULLEYS ARE IN A SAME SYSTEM CONECTED BY A BAND. SINCERELY
THANKS,
## Answer:

Your English is superior to my Spanish. My understanding of your
question is that you have a system of three pulleys with a single
band passing over all three. Assuming that the band does not
stretch and does not slip on any of the pulleys, the velocity of
the surface where the band contacts each pulley will be the same.
The angular velocity of a disk is the tangential velocity divided
by the radius so a half size pulley will turn twice as fast as a
full sized one.