Question

Consider an air shed over a city in the form of a rectangular box. The wind velocity is 5 m/sec normal to left face of the box. The length of the box along the direction of wind is 10 km and mixing height is 1 km. assuming rapid mixing of the pollutants which are conservative in nature, the concentration of the pollutants in the city would reach 63% of its final value in

(A) 2,000 sec

(B) 5,000 sec

(C) 10,000 sec

(D) 1,000 sec​

Answer 1

Answer:

c is the answer sis or bro