Final answer:
The RPM of an 8" pulley when the 3" drive pulley is spinning at 1720RPM is calculated using the formula RPM_driven = (Diameter_drive × RPM_drive) / Diameter_driven. The result is 645RPM.
Step-by-step explanation:
To find what is the RPM of an 8" pulley when the 3" drive pulley is spinning at 1720RPM, we can use the principle of pulley systems where the product of the diameter of the drive pulley and its RPM is equal to the product of the diameter of the driven pulley and its RPM. This is because pulleys connected by a belt have an inverse relationship between their sizes and the number of revolutions per minute (RPM).
The formula for calculating the RPM of the driven pulley (RPMdriven) is:
RPMdriven = (Diameterdrive × RPMdrive) ÷ Diameterdriven
Inserting the given values:
RPMdriven = (3" × 1720RPM) ÷ 8"
RPMdriven = 5160 ÷ 8
RPMdriven = 645RPM
Therefore, the RPM of an 8-inch pulley when a 3-inch drive pulley is spinning at 1720RPM is 645RPM.