Understanding Our Environment Name: _________________________ (ENVS-100) Homework Mass Balance Problems Assigned: 19 June 2017 Due: 23 June 2017 Be sure to show all your work and units for your...

Understanding Our Environment Name: _________________________ (ENVS-100) Homework Mass Balance Problems Assigned: 19 June 2017Due: 23 June 2017 Be sure to show all your work and units for your calculations. (3 points) Three creeks flow into a lake, one flows at 8.0 m3/second, one at 2.0 m3/second and the other at 1.0m3/sec. There is one stream flowing out of the lake. If the lake is in steady state conditions and has a total volume of 3,300,000m3, what is the water flowrate in the stream leaving the lake and what is the average residence time of water in the lake? Express your answers in (m3/second) and (days), respectively. Report all answers in two significant figures. (2 points) In a small lake, there is a population of 500 trout. Each month, 25 trout are born (added to the pond) and 25 trout are randomly caught (removed from the pond). These are the only processes in which the trout enter or leave the lake. Assuming the trout population is in steady state conditions, what is the average age of trout in the lake? Report all answers in two significant figures. Hint: use the residence time equation to solve this problem. (10 points) As water flows down the Colorado River, it is held in large reservoirs behind dams. A great deal of water evaporates from the river and dams, which increases the salinity of the water. Also, farming along the Colorado uses irrigation for crops; much of this water returns to the Colorado, but a salt concentration increase as a result of this process. Furthermore, municipal uses of water further increase salinity. We will look at the Colorado River between Lake Powell (behind Glen Canyon Dam) and Lake Mead (behind Hoover Dam). By carefully using the concept of Conservation of Mass, we can keep track of the amount of water in the river and the amount of salt. In this way, we can calculate the salinity in the Colorado River, and see how it changes as we go downstream. Information and Analysis Use Conservation of Mass...