Question

A 350 m^3 retention pond that holds rainwater from a shopping mall is empty at the beginning of a rainstorm. The flow rate out of the retention pond must be restricted to 320 L/min to prevent downstream flooding from a 6-hour storm. What is the maximum flow rate (in L/min) into the pond from a 6-hr storm that will not flood it? a. 5,860 L/min b. 321 L/min c. 1.290 L/min d. 7.750 L/min

Answer 1

Answer:

correct option is c. 1.290 L/min

Explanation:

given data

retention volume = 350 m³

flow rate out = 320 L/min

time = 6 hour

to find out

maximum flow rate (x)

solution

we apply here Mass rate of accumulation formula that is  

Mass rate of accumulation = mass rate of input - mass rate of output ................1

350 × 1000 L/m³ = x × ( 6hr × 60min ) -  ( 320 L × 6 hr × 60 min )

3.5 × 10³ + 4.65 × 10³ = x × 360

x = 1290 L/min

so correct option is c. 1.290 L/min