Ariver discharges 4 m3/s into a lake with a volume of 4,000,000 m3. the concentration of arsenic in the river is 1 ppb. an industry discharges 0.5 m3/s with an arsenic concentration of 20 ppb into the lake. the arsenic adheres to clay in the bottom of the lake creating an effective water concentration decay coefficient of 0.1 per day. what is the arsenic concentration leaving the lake?

Adouble-strand no. 60 roller chain is used to transmit power between a 13-tooth driving sprocket rotating at 300 rev/min and a 52-tooth driven sprocket. a) what is the allowable horsepower of this drive? b) estimate the center-to-center distance if the chain length is 82 pitches. c) estimate the torque and bending force on the driving shaft by the chain if the actual horsepower transmitted is 30 percent less than the corrected (allowable) power.