Given the concentration of p in tap water, 0.7 mg/l p, we want to model the steady-state concentration of p in prospect park lake. we will use a simple model. assume that the only p input is from tap water and the only p loss mechanism is through settling of precipitated p. the settling rate can be represented as vs with units of m/s. also assume that the lake is well-mixed. draw a schematic of the lake, and write a mass balance equation for p in the lake. the mass balance equation should be written with the variables q (i. e., assume qin = qout), asurface (the surface area of the lake), vs, cin, and clake (i. e., the concentration in the lake = the concentration in the lake outlet). hint: there will be two terms for mass rate out, and no reaction term. one of terms for mass rate out should include the variables vs and asurface (make sure the units work out to be mass/time).