Final answer:
The diameter of the pulley that must be put on the fan is 18 inches.
Step-by-step explanation:
To find the diameter of the pulley that must be put on the fan, use the formula:
D1 * N1 = D2 * N2 ( Where D1 = diameter of the motor pulley, N1 = speed of the motor pulley, D2 = diameter of the fan pulley, and N2 = speed of the fan pulley.)
Given that the motor pulley has a diameter of 6.0 inches and is turning at 1890 rpm, and the fan pulley needs to turn at 630 rpm, we can substitute these values into the formula:
(6.0 inches) * (1890 rpm) = D2 * (630 rpm)
Solving for D2, we get:
D2 = (6.0 inches * 1890 rpm) / 630 rpm
D2 = 18.0 inches