posted by Ashley
Consider a lake of constant volume 12200 km^3, which at time t contains an amount y(t) tons of pollutant evenly distributed throughout the lake with a concentration y(t)/12200 tons/km^3.
assume that fresh water enters the lake at a rate of 67.1 km^3/yr, and that water leaves the lake at the same rate. suppose that pollutants are added directly to the lake at a constant rate of 550 tons/yr.
A) write a differential equation for y(t).
B) solve the differential equation for initial condition y(0)=200000 to get an expression for y(t). Use your solution to y(t) to describe in practical terms what happens to the amount of pollutants in the lake as t goes from 0 to infinity.