Calculating velocity pressure is tedious and one has to remember to convert lbm to lbf because...

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Calculating velocity pressure is tedious and one has to remember to convert lbm to lbf because pressure is force per area. For air duct calculations there is a convenient equation, which is as follows: where: V is the velocity in feet per minute (fpm) P = (Factor) P is the velocity pressure in inches of water (in. wg) Determine the correct factor, starting from the following equation: P where: Air density, p=0.0751 lb/ft PV = 29 Remember that: lb=32.17 lbft/s (where 32.17 ft/s is the acceleration of gravity) Compare your answer to the following factor: P 2 V = v 4005 Calculating velocity pressure is tedious and one has to remember to convert lbm to lbf because pressure is force per area. For air duct calculations there is a convenient equation, which is as follows: where: V is the velocity in feet per minute (fpm) P = (Factor) P is the velocity pressure in inches of water (in. wg) Determine the correct factor, starting from the following equation: P where: Air density, p=0.0751 lb/ft PV = 29 Remember that: lb=32.17 lbft/s (where 32.17 ft/s is the acceleration of gravity) Compare your answer to the following factor: P 2 V = v 4005