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Allushta [10]
3 years ago
12

Plateau Creek carries 5.0 m^3 /s of water with a selenium (Se) concentration of 0.0015 mg/L. A farmer withdraws water at a certa

in flowrate (m3 /s) from the creek for irrigation. After using the water, half of the water withdrawn returns to the creek and contains 1.00 mg/L of Se. Fish in the creek are sensitive to Se levels over 0.04 mg/L.
Required:

How much water (m3 /s) can the farmer withdraw from the stream to maintain Se at 0.04 mg/L after the contaminated water is returned to the creek?
Engineering
1 answer:
Bond [772]3 years ago
7 0

Answer:

The correct answer is "4.8137 m³". The further explanation is given below.

Explanation:

Firstly we have to calculate the concentration of Se:

C = 0.0015 \ mg/L\times \frac{1g}{1000 mg}\times \frac{1 \ mol}{79 \ g}

   =1.9\times 10^{-8} \ mol/L

Concentration the fish can take:

=0.04 \ mg/L\times \frac{1 \ g}{1000mg}\times \frac{1 \ mol}{79 \ g}

According to the general dilution principle will be:

⇒  M_1V_1 = M_2V_2

The volume that can take the farmer will be:

V_2 = 1.9\times 10^{-8} M\times  \frac{5\times 10^3 \ L}{5.1\times 10-7 M}

    =186.27 \ L

On converting this into m³, we get

= 0.18627 \ m^3

Finally the volume the farmer can remove would be:

V = 5-0.18627

   = 4.8137 \ m^3

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A saturated 1.5 ft3 clay sample has a natural water content of 25%, shrinkage limit (SL) of 12% and a specific gravity (GS) of 2
Svetllana [295]

79 f t^{3} is the volume of the sample when the water content is 10%.

<u>Explanation:</u>

Given Data:

V_{1}=100\ \mathrm{ft}^{3}

First has a natural water content of 25% = \frac{25}{100} = 0.25

Shrinkage limit, w_{1}=12 \%=\frac{12}{100}=0.12

G_{s}=2.70

We need to determine the volume of the sample when the water content is 10% (0.10). As we know,

V \propto[1+e]

\frac{V_{2}}{V_{1}}=\frac{1+e_{2}}{1+e_{1}}  ------> eq 1

e_{1}=\frac{w_{1} \times G_{s}}{S_{r}}

The above equation is at S_{r}=1,

e_{1}=w_{1} \times G_{s}

Applying the given values, we get

e_{1}=0.25 \times 2.70=0.675

Shrinkage limit is lowest water content

e_{2}=w_{2} \times G_{s}

Applying the given values, we get

e_{2}=0.12 \times 2.70=0.324

Applying the found values in eq 1, we get

\frac{V_{2}}{100}=\frac{1+0.324}{1+0.675}=\frac{1.324}{1.675}=0.7904

V_{2}=0.7904 \times 100=79\ \mathrm{ft}^{3}

7 0
3 years ago
2. Write a Java program that generates a new string by concatenating the reversed substrings of even indexes and odd indexes sep
Nana76 [90]

Answer:

  1. public class Main {
  2.    public static void main(String[] args) {
  3.        String testString = "abscacd";
  4.        String evenStr = "";
  5.        String oddStr = "";
  6.        for(int i=testString.length() - 1; i >= 0; i--){
  7.            if(i % 2 == 0){
  8.                evenStr += testString.charAt(i);
  9.            }
  10.            else{
  11.                oddStr += testString.charAt(i);
  12.            }
  13.        }
  14.        System.out.println(evenStr + oddStr);
  15.    }
  16. }

Explanation:

Firstly, let declare a variable testString to hold an input string "abscacd" (Line 1).

Next create another two String variable, evenStr and oddStr and initialize them with empty string (Line 5-6). These two variables will be used to hold the string at even index and odd index, respectively.

Next, we create a for loop that traverse the characters of the input string from the back by setting initial position index i to  testString.length() - 1  (Line 8). Within the for-loop, create if and else block to check if the current index, i is divisible by 2, (i % 2 == 0), use the current i to get the character of the testString and join it with evenStr. Otherwise, join it with oddStr (Line 10 -14).

At last, we print the concatenated evenStr and oddStr (Line 18).  

4 0
2 years ago
Question 9.1 from the textbook. Consider the following workload: Process Burst Time Priority Arrival Time P1 50 4 0 P2 20 1 20 P
Marizza181 [45]

Answer:

Explanation:

The schedule using shortest remaining time, non-preemptive priority and round Robin with quantum number 30 is shown in the attached file, please kindly go through it to access the answer.

5 0
3 years ago
What is the minimum efficiency of a functioning current-model catalytic converter? a. 60% b. 75% c. 80% d. 90%
slamgirl [31]

Answer:

d. 90%

Explanation:

As we know that internal combustion engine produce lot's of toxic gases to reduce these toxic gases in the environment a device is used and this device is know as current modeling converter.

Generally the efficiency of current model catalytic converter is more than 90%.But the minimum efficiency this converter is 90%.

So option d is correct.

d. 90%

7 0
3 years ago
Which term describes a Cloud provider allowing more than one company to share or rent the same server?
svlad2 [7]

Answer:

multitenancy is the term.

6 0
2 years ago
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