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3 years ago

How long did it take the Niagara power plant to be built

Engineering

2 answers:

TiliK225 [7]3 years ago

8 0

It took about 3 years for the Niagara power plant to be built.

Hatshy [7]3 years ago

6 0

Answer: 64 years

Explanation:

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Entropy change is evaluated using Eq. 6.2a based on an internally reversible process. Can the entropy change between two states

Vadim26 [7]

Answer:

YES

Explanation:

Entropy is an extensive property of the system entropy change that value of entropy change can be determined for any process between the states whether reversible or not. i have attached the formula to calculate entropy change which is independent of whether the system is reversible or not and can be determined for any process.

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4 years ago

A 100 kmol/h stream that is 97 mole% carbon tetrachloride (CCL) and 3% carbon disulfide (CS2) is to be recovered from the bottom

Ugo [173]

Answer: oop

Explanation:oop

7 0

3 years ago

The Double.parseDouble() method requires a String argument, but it fails if the String cannot be converted to a floating-point n

LuckyWell [14K]

Answer:

import java.util.Scanner;
public class TryToParseDouble {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
double num;
try{
System.out.print("Input a number: ");
num = Double.parseDouble(input.nextLine());
}catch(NumberFormatException e){
num = 0;
System.out.println("Invalid input! It should be a number in double type");
}
System.out.println(num);
}
}

Explanation:

Firstly, create a Scanner object to get user input (Line 5).

Next, create a try block and prompt user to input a number and use Double.parseDouble() method to convert the input to double type in the block (Line 8-10).

Next, create a catch block to catch a NumberFormatException. In the Catch block, set the num to zero and then print out a message to inform user about the invalid input (Line 12-14).

Lastly, display the number (Line 16).

5 0

3 years ago

Find the dy/dx using implicit differentiation

irina [24]

Answer:

dy/dx = (1 − 2x + 8y) / (4 + 3x − 12y)

Explanation:

d/dx (x − 4y) = d/dx (e^(2x + 3y − 1))

1 − 4 dy/dx = e^(2x + 3y − 1) (2 + 3 dy/dx)

Since x − 4y = e^(2x + 3y − 1):

1 − 4 dy/dx = (x − 4y) (2 + 3 dy/dx)

1 − 4 dy/dx = 2 (x − 4y) + 3 (x − 4y) dy/dx

1 − 4 dy/dx = 2x − 8y + (3x − 12y) dy/dx

1 − 2x + 8y = (4 + 3x − 12y) dy/dx

dy/dx = (1 − 2x + 8y) / (4 + 3x − 12y)

6 0

3 years ago

Problem 4.041 SI Refrigerant 134a enters an insulated compressor operating at steady state as saturated vapor at -26oC with a vo

Rom4ik [11]

Answer:

0.0297M^3/s

W=68.48kW

Explanation:

Hello! To solve this problem, we must first find all the thermodynamic properties at the input (state 1) and the compressor output (state 2), using the thermodynamic tables

Through laboratory tests, thermodynamic tables were developed, these allow to know all the thermodynamic properties of a substance (entropy, enthalpy, pressure, specific volume, internal energy etc ..)

through prior knowledge of two other properties such as pressure and temperature.

state 1

X=quality=1

T=-26C

density 1=α1=5.27kg/m^3

entalpy1=h1=234.7KJ/kg

state 2

T2=70

P2=8bar=800kPa

density 2=α2=31.91kg/m^3

entalpy2=h2=306.9KJ/kg

Now to find the flow at the outlet of the compressor, we remember the continuity equation that states that the mass flow is equal to the input and output.

m1=m2

(Q1)(α1)=(Q2)(α2)

$\frac{(Q1)(\alpha 1) }{\alpha 2} =Q2\\Q2=\frac{(0.18)(5.27) }{31.91} =0.0297M^3/s$

the volumetric flow rate at the exit is 0.0297M^3/s

To find the power of the compressor we use the first law of thermodynamics that says that the energy that enters must be equal to the energy that comes out, in this order of ideas we have the following equation

W=m(h2-h1)

m=Qα

W=(0.18)(5.27)(306.9-234.7)

W=68.48kW

the compressor power is 68.48kW

4 0

3 years ago