Question

A power plant emits a pollutant X to the atmosphere at a constant rate E (kg s-1) starting at time t = 0. X is removed from the atmosphere by chemical reaction with a first- order rate constant k (s-1).

a. Let m be the mass of X in the atmosphere resulting from the power plant emissions. Write an equation for m(t). Plot your results. What is the steady-state value m??

b. Show that the atmospheric lifetime of X is ? =1/k. What is the ratio m(t)/m? at time t = ?? At time t = 3??

c. If the power plant were to suddenly cease operations, how long would it take for m to decrease from its steady state value m? to 5% of that value?

P/S: I need answer for question c. Thanks.

Answer 1