The earth has a vertical electric field at the surface, pointing down, that averages 102 N/C. This field is maintained by various atmosphericprocesses, including lightning. What is the excess charge on the surface of the earth? inC

Explanation:

From the question we are told that

     The  electric filed is    

Generally according to Gauss law

=>  

Given that  the electric field is pointing downward  , the equation become

Here   is the excess charge on the surface of the earth

          is the surface  area of the of the earth which is mathematically represented as

Where r is the radius of the earth which has a value

 substituting values

So

Here s the permitivity of free space with value

substituting values

15.3 cos 65 degrees trig

area of focus