7. An instrument is installed along a major water distribution pipe line to detect potential contamination from terrorist threats. A 2.54-cm-diameter pipe connects the instrument to the water distribution pipe.

The connecting pipe is 20.0 m long. Water from the distribution pipe is pumped through the instrument and then discharged to a holding tank for verification analysis and proper disposal If the flow rate of the water in the sample line is 1.0 L/min, how many minutes will it take a sample from the distribution pipe to reach the instrument. Use the following relationship to determine the speed of the water in the sample pipe: If the instrument uses 10 mL for sample analysis, how many liters of water must pass through the sampler before it detects a contaminant in the pipe? A = area of pipe, m² flow rate of water in pipe, m³ /s where u = speed of water in pipe, m/s u = Q/A