A pulley of diameter 49.0 in revolves at 1860 rpm. What is the diameter of a second pulley, in inches, if it rotates at 620 rpm?

Answer;

First pulley;

Diameter; 49.0, revolutions 1860 rpm

Second pulley;

Diameter; x; revolutions 620 rpm

To get the diameter of the second pulley;

= (Diameter of the first * Revolutions of the first) / revolutions of the second.

= (49 * 1860) / 620

= 147

Thus; the diameter of the second pulley is 147.

You would most likely use the formula pi (d)