A standard 12 inch garden hose has a flow rate of 9 gpm a Wh

A standard 1/2 inch garden hose has a flow rate of 9 gpm.  

a. What is the velocity of the water exiting the hose in ft/s and m/s? 4.48 m/s = 14.7 ft/s

b. What is the mass flow rate of the water exiting the hose in lbm/s and kg/s? 0.57 kg/s = 1.25 lbm/s

Solution

VELOCITY =    ( 4 X FLOW RATE) / ( X ( PIPE DIA ) ²   )

                   = ( 4 x 9 GPM ) /   ( 3.14 X ( 0.5 inch ) ² )  

                  = ( 4 x 0.0005678 meter cube )   /   ( 3.14 x ( 0.0127   meter) ² )  

            VELOCITY           = 4.48 m/s     

              VELOCITY         = 14.706   ft / sec

MASS FLOW =   DENSITY x AREA x VELOCITY   

AREA OF CIRCLE = PI x R ²    = 3.14 x    (  1/4   ) ² INCH    // * DIA 1/2 INCH = 1/4 REDIUS ///

                 =     3.14 *   ( 0.00635 )²    METER  

                 AREA = 0.000126613

DENSITY OF WATER   = 1000 KG / M 3       

VELOCITY AS PER OUR PREVIOUS CALCULATION = 4.48 m/s

MASS FLOW =   DENSITY x AREA x VELOCITY   

            = 1000 KG / M 3      *   0.000126613 M2     *    4.48 m/s

MASS FLOW =   0.57 kg/s    

MASS FLOW =   1.25 lbm/s