Engineers sometimes add chlorine to pipes to disinfect water. It is desired to achieve four logs of kill. This means that the effluent concentration of microoganisms is 10^-4 times the influent. If teh flow is 40ft^3/min, calculate teh volume of teh pipe required to achieve four logs of kill in the first-order rate constant for disinfection is 0.5 min^-1. If the pipe is 3 ft in diameter how long would the pipe have to be