Consider the concentration of lead (Pb) in a lake, using a simplified CMFR model. The lake has a river flowing into it and another flowing out of it, and the water level in the lake is constant. The major sources of lead in the lake are direct deposition from the atmosphere and surface runoff carried into the lake with the river. The major removal process is river outflow. Leaded gasoline was widely used for about 35 years (roughly 1950-1985), leading to a high influx of lead into the lake during those years.

Lake Volume = 2 x 10^9 m3
River inflow = 1.2 x 10^8 m3/y
Pb, in lake water, 1950 = 2 ppb
Pb in influent water, 1950-1985 = 30 ppb
Pb in influent water, 1985-2050 = 5 ppb
Pb deposition from atmosphere
1950-1985= 3,000 kg/y
1985-2050= 300 kg/y

Derive the equation that describe the concentration in the lake of water as function of time beginning in 1950.

answer:

31

explanation:

answer:

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answer:

not sure

explanation:

answer:

// here is code in C++.

#include <bits/stdc++.h>

using namespace std;

//main function

int main()

{

  // variable

 int n;

 cout<<"enter a number:";

 // read the input

 cin>>n;

 // find the square root of the absolute value

 float square_root=sqrt(abs(n));

 // print the square_root

 cout<<"square root of "<<n<<" is: "<<square_root<<endl;

  return 0;

}

Explanation:

Read a number from user and assign it to "n".Then find its absolute value with abs() function.Then calculate the square root of the absolute value with sqrt() function.Print the square root of the number.

Output:

enter a number:-17

square root of -17 is: 4.12311

                                                         This is easy

                                                     sinserly Natalie 7 grader (this is not that hard)