The Manning formula is an empirical formula estimating the average velocity of a liquid flowing in a conduit that does not completely enclose the liquid, i. The question is asking for the K-Factor, so we know to use: K = Q ÷ √P. Velocity. 17( / ) 5. Hydraulic. . The majority of pump operations are performed through a time consuming process of trial and error, which often results in increased fire size, increased radio traffic and equipment damage. .