Chapter 4.3, Problem 89E

Total pollution. A factory is polluting a lake in such a way that the rate of pollution entering the take after t months is

$N^{\prime }\left(t\right)=280t^{3/2}$,

Where $N\left(t\right)$ is the total number of pounds of pollutions in the lake after t months.

How many pounds of pollutions enter the lake in 16 months?

b. An environmental board tells the factory that it must begin cleanup procedures after 50,000lb of pollutants have entered the lake. After what length of time will this occur?