Consider laminar, fully developed flow in a channel of constant surface temperature Ts. For a given mass flow rate and channel length, determine which rectangular channel, b/a = 1.0, 1.43, or 2.0, will provide the highest heat transfer rate. Is this heat transfer rate greater than, equal to, or less than the heat transfer rate associated with a circular tube? answer: b/a=2

Answers

Answer 1

Answer:

Please see attachment.

Explanation:

Consider Laminar, Fully Developed Flow In A Channel Of Constant Surface Temperature Ts. For A Given Mass
Consider Laminar, Fully Developed Flow In A Channel Of Constant Surface Temperature Ts. For A Given Mass

Related Questions

A large-particle composite consisting of tungsten particles within a copper matrix is to be prepared. If the volume fractions of tungsten and copper are 0.90 and 0.10, respectively, estimate the upper limit for the specific stiffness of this composite given the data that follow. Specific Gravity Modulus of Elasticity (GPa)
Copper 8.9 110
Tungsten 19.3 407

Answers

The upper limit for the specific stiffness of this composite is approximately 20.208 GPa.

Specific stiffness of composite = Volume fraction of copper * Specific stiffness of copper + Volume fraction of tungsten * Specific stiffness of tungsten

Specific stiffness of composite = [tex](0.10 * (110 / 8.9)) + (0.90 * (407 / 19.3))[/tex]

Now, calculate the specific stiffness of the composite.

Specific stiffness of composite = [tex](0.10 * (110 / 8.9)) + (0.90 * (407 / 19.3))[/tex]

Specific stiffness of composite ≈[tex](0.10 * 12.36) + (0.90 * 21.08)[/tex]

Specific stiffness of composite ≈ [tex]1.236 + 18.972[/tex]

Specific stiffness of composite ≈ 20.208 GPa

So, the upper limit for the specific stiffness of this composite is approximately 20.208 GPa.

A pressure gage and a manometer are connected to a compressed air tank to measure its pressure. If the reading on the pressure gage is 11 kPa, determine the distance h between the two fluid levels of the water filled manometer. Assume the density of water is 1000 kg/m3 and the atmospheric pressure is 101 kPa.Quiz 3

Answers

Answer:

h=1.122652m

Explanation:

Assuming density of air = 1.2kg/m³

the differential pressure is given by:

[tex]h^{i} =h(\frac{density of manometer}{density of flowing air}-1)\\h^{i} =h(\frac{1000}{1.2}-1)\\ h^{i}=832.33h...(1)\\\\but\\ h^{i} =\frac{change in pressure}{air density*g} \\\\h^{i} =\frac{11*10^3}{1.2*9.81}\\\\h^{i}= 934.42...(2)\\\\equating, \\\\934.42=832.33h\\\\h=1.122652m[/tex]

The distance  h  between the two fluid levels of the water-filled manometer is approximately 1.121 meters.

To determine the distance  h  between the two fluid levels of the water-filled manometer, we need to use the pressure readings from both the pressure gauge and the manometer. Here's how we can approach the problem:

Given:

- Reading on the pressure gauge: [tex]\( P_{gauge} = 11 \, \text{kPa} \)[/tex]- Atmospheric pressure: [tex]\( P_{atm} = 101 \, \text{kPa} \)[/tex]

- Density of water: [tex]\( \rho = 1000 \, \text{kg/m}^3 \)[/tex]

- Acceleration due to gravity: [tex]\( g = 9.81 \, \text{m/s}^2 \)[/tex]

Step-by-Step Solution:

1. Convert the gauge pressure to absolute pressure:

[tex]\[ P_{absolute} = P_{gauge} + P_{atm} \][/tex]

[tex]\[ P_{absolute} = 11 \, \text{kPa} + 101 \, \text{kPa} = 112 \, \text{kPa} \][/tex]

2. Determine the pressure difference between the air tank and atmospheric pressure:

  The pressure difference [tex](\( \Delta P \))[/tex] that the manometer measures is equal to the gauge pressure:

[tex]\[ \Delta P = P_{absolute} - P_{atm} = 112 \, \text{kPa} - 101 \, \text{kPa} = 11 \, \text{kPa} \][/tex]

3. Use the pressure difference to find the height ( h ):

  The pressure difference is related to the height ( h ) of the water column by the hydrostatic equation:

 [tex]\[ \Delta P = \rho g h \][/tex]

  Solving for ( h ):

[tex]\[ h = \frac{\Delta P}{\rho g} \][/tex]

  Convert [tex]\(\Delta P\)[/tex] to Pascals [tex](since \(1 \, \text{kPa} = 1000 \, \text{Pa}\))[/tex]:

 [tex]\[ \Delta P = 11 \, \text{kPa} = 11000 \, \text{Pa} \][/tex]

  Now, calculate ( h ):

[tex]\[ h = \frac{11000 \, \text{Pa}}{1000 \, \text{kg/m}^3 \times 9.81 \, \text{m/s}^2} \][/tex]

[tex]\[ h \approx \frac{11000}{9810} \, \text{m} \][/tex]

[tex]\[ h \approx 1.121 \, \text{m} \][/tex]

Write a program that uses the function isPalindrome given below. Test your program on the following strings: madam, abba, 22, 67876, 444244, trymeuemyrt. Modify the function isPalindrome given so that when determining whether a string is a palindrome, cases are ignored, that is, uppercase and lowercase letters are considered the same. bool isPalindrome(string str)
{
int length = str.length();

for (int i = 0; i < length / 2; i++)
{
if (str[i] != str[length - 1 - i] )
return false;
}

return true;
}

Answers

Final answer:

The revised isPalindrome function now considers uppercase and lowercase letters as the same, correctly identifying palindromes regardless of case. It first converts the input string to all lowercase and then checks for palindrome properties.

Explanation:

Understanding Palindromes in Programming

A palindrome is a sequence of characters that reads the same forwards and backwards. The provided isPalindrome function is designed to check if a given string is a palindrome. However, the function needs to be modified to disregard the case of the letters, allowing 'Madam' and 'madam' to both be recognized as palindromes.

To achieve this, we can modify the function by converting the input string to all lowercase or uppercase before the comparison. Here's the revised version of the function:

bool isPalindrome(string str) {
 transform(str.begin(), str.end(), str.begin(), ::tolower);
 int length = str.length();
 for (int i = 0; i < length / 2; i++) {
   if (str[i] != str[length - 1 - i])
     return false;
 }
 return true;
}

Now, when this modified function is tested with the strings 'madam', 'abba', '22', '67876', '444244', and 'trymeuemyrt', it will correctly identify the palindromes regardless of case.

Palindromes, isPalindrome function modification for case-insensitivity, Examples of palindromes.

Palindromes are sequences of letters or words that read the same forwards and backwards. They can be found in various contexts, including DNA sequences. The objective of the given program is to determine if a given string is a palindrome, which remains the same when read backward.

The modified function isPalindrome checks if a string is a palindrome while ignoring case differences, treating uppercase and lowercase letters as the same. This modification allows the function to correctly identify palindromes regardless of letter casing.

Examples such as 'madam', 'abba', 'trymeuemyrt' correspond to palindromes while considering the modified function's case-insensitive behavior, showcasing the effectiveness of the updated algorithm

A pipe leads from a storage tank on the roof of a building to the ground floor. The absolute pressure of the water in the storage tank where it connects to the pipe is 3.0×105Pa, the pipe has a radius of 1.0 cm where it connects to the storage tank, and the speed of flow in this pipe is 1.6 m/s. The pipe on the ground floor has a radius of 0.50 cm and is 9.0 m below the storage tank. Find the speed of flow in the pipe on the ground floor.

Answers

Answer:

6.4 m/s

Explanation:

From the equation of continuity

A1V1=A2V2 where A1 and V1 are area and velocity of inlet respectively while A2 and V2 are the area and velocity of outlet respectively

[tex]A1=\pi (r1)^{2}[/tex]

[tex]A2=\pi (r2)^{2}[/tex]

where r1 and r2 are radius of inlet and outlet respectively

v1 is given as 1.6 m/s

Therefore

[tex]\pi (0.01)^{2}\times 1.6 = \pi (0.005)^{2}v2[/tex]

[tex]V2=\frac {\pi (0.01)^{2}\times 1.6}{\pi (0.005)^{2}}=6.4 m/s[/tex]

A film of paint 3 mm thick is applied to a surface inclined above the horizontal at an angle \theta. The paint has rheological properties of a Bingham plastic with yield stress 15 Pa and \mu[infinity]= 60 cP. With a specific gravity of 1.3, at what angle \ theta will the paint start to flow down the surface?

Answers

Answer:

[tex]\theta = 23.083 degree[/tex]

Explanation:

Given data:

yield stress [tex]\tau_y  = 15 Pa[/tex]

thickness t = 3 mm

[tex]\mu = 60 cP = 60\times 10^{-2} P[/tex]

G= 1.3

[tex]\rho_{point} = G \times \rho_{water}[/tex]

                     [tex]=1.3 \times 1000 = 1300 kg/m^3[/tex]

[tex]\tau = \tau_y + mu \frac{du}{dy}[/tex]

for point flow [tex]\frac{du}{dy} = 0[/tex]

[tex]\tau = \tau_y = 15 N/m^2[/tex]

[tex]\tau = \frac{force}{area}[/tex]

       [tex]= \frac{weight of point . sin\theta}{area} = \frac{\rho_{point} . volume. sin\theta}{area}[/tex][/tex]

[tex]15 = \frac{1300 \times 9.8 \times A\times t \times sin\theta}{A}[/tex]

solving for theta value

[tex]sin\theta = 0.392[/tex]

[tex]\theta =sin^{-1} 0.392[/tex]

[tex]\theta = 23.083 degree[/tex]

A rapid sand filter has a loading rate of 8.00 m/h, surface dimensions of 10 m ´ 8 m, an effective filtration rate of 7.70 m/h. A complete filter cycle duration is 52 h and the filter is rinsed for 20 minutes at the start of each cycle. a. What flow rate (m3 /s) does the filter handle during production? b. What volume of water is used for backwashing plus rinsing the filter in each filter cycle?

Answers

Answer:

Explanation:

given data

loading rate = 8.00 m/h

filtration rate = 7.70 m/h

dimensions = 10 m × 8 m

filter cycle duration = 52 h

time = 20 min

to find out

flow rate  and  volume of water is used for back washing plus rinsing the filter  

solution  

we consider here production efficiency is 96%

so here flow rate will be  

flow rate = area × rate of filtration  

flow rate = 10 × 8 × 7.7  

flow rate = 616 m³/h

and  

we know back washing generally 3 to 5 % of total volume of water per cycle so  

volume of water is = 616 × 52

volume of water is  32032 m³

and  

volume of water of back washing is = 4% of 32032  

volume of water of back washing is 1281.2 m³

As Jamar prepares for a face-to-face interview, he begins to brainstorm a list of stories he can use to highlight his skills and qualifications. What types of stories should he rehearse? Check all that apply. Stories that criticize his previous employers Stories that discuss how he handled a tough interpersonal situation Stories that describe his religious beliefs and marital status Stories that discuss how he dealt with a crisis Stories that illustrate how he went above and beyond expectations

Answers

Answer:

Stories that discuss how he dealt with a crisis

Stories that illustrate how he went above and beyond expectations

Stories that discuss how he handled a tough interpersonal situation

Explanation:

For effective story-telling during an interview, Jamar needs to highlight stories by discussing how he dealt with certain crisis which relates to the job and tell the panel why he opted for a particular solution. The solution should provide a long-term solution to the crisis. He also needs to illustrate stories on how he went above and beyond expectations  to prove that he's creative. Moreover, it's important that he highlights how he handled a tough interpersonal situation to show how he deals with situations at a personal level.

You are using a Geiger counter to measure the activity of a radioactive substance over the course of several minutes. If the reading of 400. counts has diminished to 100. counts after 66.7 minutes , what is the half-life of this substance? Express your answer with the appropriate units.

Answers

Answer: 33.35 minutes

Explanation:

A(t) = A(o) *(.5)^[t/(t1/2)]....equ1

Where

A(t) = geiger count after time t = 100

A(o) = initial geiger count = 400

(t1/2) = the half life of decay

t = time between geiger count = 66.7 minutes

Sub into equ 1

100=400(.5)^[66.7/(t1/2)

Equ becomes

.25= (.5)^[66.7/(t1/2)]

Take log of both sides

Log 0.25 = [66.7/(t1/2)] * log 0.5

66.7/(t1/2) = 2

(t1/2) = (66.7/2 ) = 33.35 minutes

Water flows in a constant diameter pipe with the following conditions measured:
At section (a) pa = 31.1 psi and za = 56.7 ft; at section (b) pb = 27.3 psi and zb = 68.8 ft.
(a) Determine the head loss from section (a) to section (b).
(b) Is the flow from (a) to (b) or from (b) to (a)?

Answers

Answer:

a) [tex]h_L=-3.331ft[/tex]

b) The flow would be going from section (b) to section (a)

Explanation:

1) Notation

[tex]p_a =31.1psi=4478.4\frac{lb}{ft^2}[/tex]

[tex]p_b =27.3psi=3931.2\frac{lb}{ft^2}[/tex]

For above conversions we use the conversion factor [tex]1psi=144\frac{lb}{ft^2}[/tex]

[tex]z_a =56.7ft[/tex]

[tex]z_a =68.8ft[/tex]

[tex]h_L =?[/tex] head loss from section

2) Formulas and definitions

For this case we can apply the Bernoulli equation between the sections given (a) and (b). Is important to remember that this equation allows en energy balance since represent the sum of all the energies in a fluid, and this sum need to be constant at any point selected.

The formula is given by:

[tex]\frac{p_a}{\gamma}+\frac{V_a^2}{2g}+z_a =\frac{p_b}{\gamma}+\frac{V_b^2}{2g}+z_b +h_L[/tex]

Since we have a constant section on the piple we have the same area and flow, then the velocities at point (a) and (b) would be the same, and we have just this expression:

[tex]\frac{p_a}{\gamma}+z_a =\frac{p_b}{\gamma}+z_b +h_L[/tex]

3)Part a

And on this case we have all the values in order to replace and solve for [tex]h_L[/tex]

[tex]\frac{4478.4\frac{lb}{ft^2}}{62.4\frac{lb}{ft^3}}+56.7ft=\frac{3931.2\frac{lb}{ft^2}}{62.4\frac{lb}{ft^3}}+68.8ft +h_L[/tex]

[tex]h_L=(71.769+56.7-63-68.8)ft=-3.331ft[/tex]

4)Part b

Analyzing the value obtained for [tex]\h_L[/tex] is a negative value, so on this case this means that the flow would be going from section (b) to section (a).

A small circular plate has a diameter of 2 cm and can be approximated as a blackbody. To determine the radiation from the plate, a radiometer is placed normal to the direction of viewing from the plate at a distance of 50 cm. If the radiometer measured an irradiation of 129 W/m2 from the plate, determine the temperature of the plate. Take the Stefan-Boltzmann constant as σ = 5.67 x 10-8 W/m2·K4.The temperature of the plate is______________.

Answers

Answer: Temperature T = 218.399K.

Explanation:

Q= 129W/m2

σ = 5.67 EXP -8W/m2K4

Q= σ x t^4

t = (Q/σ)^0.25

t= 218.399k

A 15 ft high vertical wall retains an overconsolidated soil where OCR-1.5, c'-: O, ф , --33°, and 1 1 5.0 lb/ft3.

Determine the magnitude and location of the thrust on the wall, assuming that the soil is at rest.

Answers

Answer:

magnitude of thrust uis  11061.65 lb/ft

location is 5 ft from bottom

Explanation:

Given data:

Height of vertical wall is 15 ft

OCR  is 1.5

[tex]\phi = 33^o[/tex]

saturated uit weight[tex] \gamma_{sat} = 115.0 lb/ft^3[/tex]

coeeficent of earth pressure [tex]K_o[/tex]

[tex]K_o = 1 -sin \phi[/tex]

        = 1 - sin 33 = 0.455

for over consolidate

[tex]K_{con} = K_o \times OCR[/tex]

            [tex] = 0.455 \times 1.5 = 0.683[/tex]

Pressure at bottom of wall is

[tex]P =K_{con} \times (\gamma_{sat} - \gamma_{w}) + \gamma_w \times H[/tex]

   [tex]= 0.683 \times (115 - 62.4) \times 15 + 62.4 \times 15[/tex]

P = 1474.88 lb/ft^3

Magnitude pf thrust is

[tex]F= \frac{1}{2} PH[/tex]

   [tex]=\frac{1}{2} 1474.88\times 15 = 11061.65 lb/ft[/tex]

the location must H/3 from bottom so

[tex]x = \frac{15}{3} = 5 ft[/tex]

Given a dictionary d and a list lst, remove all elements from the dictionary whose key is an element of lst. For example, given the dictionary {1:2, 3:4, 5:6, 7:8} and the list [1, 7], the resulting dictionary would be {3:4, 5:6}. Assume every element of the list is a key in the dictionary.

Answers

This function remove_elements takes a dictionary d and a list lst as input and removes all key-value pairs from d where the key is an element of lst is written below

Writing the program in Python

The program can be written by iterating through the list and removing the corresponding key-value pairs from the dictionary.

The python function that removes all required elements from the dictionary is as follows

def remove_elements(d, lst):

   for key in lst:

       if key in d:

           del d[key]

   return d

# Example usage

d = {1: 2, 3: 4, 5: 6, 7: 8}

lst = [1, 7]

result = remove_elements(d, lst)

print(result)

Question

Given a dictionary d and a list lst, remove all elements from the dictionary whose key is an element of lst.

For example, given the dictionary {1:2, 3:4, 5:6, 7:8} and the list [1, 7], the resulting dictionary would be {3:4, 5:6}.

Assume every element of the list is a key in the dictionary.

Write the program in Python

Write a program that generates a random number and asks the user to guess what the number is. If the user's guess is higher than the random number, the program should display "Too high, try again." If the user's guess is lower than the random number, the program should display "Too low, try again." The program should use a loop that repeats until the user correctly guesses the random number.

Answers

Answer:

import java.util.Scanner;

import java.util.Random;

public class GuessingGame

{

public static void main(String [] args)

{

Scanner kb = new Scanner(System.in);

Random rand = new Random();

int num;

int guess = 0;

int guesses = 0;

char yorn;

String in;

do

{

num = rand.nextInt(100) + 1;

guesses = 0;

do

{

System.out.println("Guess what number I have (1-100)? ");

guess = kb.nextInt();

guesses ++;

if(guess > num) {

System.out.println("Too high, try again.");

} else if(guess< num) {

System.out.println("Too low, try again.");

} else {

System.out.println("You're right, the number is " + num);

System.out.println("You guessed " + guesses + " times");

}

}

while(guess!=num);

in=kb.nextLine();

System.out.print("Play again(Y/N)? ");

in=kb.nextLine();

yorn=in.charAt(0);

}while(yorn=='Y'||yorn=='y');

}

}

The article "Some Parameters of the Population Biology of Spotted Flounder (Ciutharus linguatula Linnaeus, 1758) in Edremit Bay (North Aegean Sea)" (D. Turker, B. Bayhan, etal., Turkish Journal of Veterinary and Animal Science, 2005:1013-1018) reports that a sample of 482 female spotted flounder had an average weight of 20.95 g with a standard deviation of 14.5 g, and a sample of 614 male spotted flounder had an average weight of 22.79 g with a standard deviation of 15.6 g. Can you conclude that the mearn weight of male spotted flounder is greater than that of females?

Answers

Based on the higher male average weight and large sample sizes, we expect a relatively large positive t-statistic and a statistically significant p-value (low p-value).

Formulate the hypothesis:

Null hypothesis (H0): μm = μf (The mean weight of male spotted flounder (μm) is equal to the mean weight of female spotted flounder (μf))

Alternative hypothesis (H1): μm > μf (The mean weight of male spotted flounder is greater than the mean weight of female spotted flounder) (One-tailed test)

Calculate the pooled variance (assuming unequal variances):

Sp^2 = [(nf - 1) * σf^2 + (nm - 1) * σm^2] / (nf + nm - 2)

nf = Female sample size (482)

nm = Male sample size (614)

σf = Female standard deviation (14.5 g)

σm = Male standard deviation (15.6 g)

3. Calculate the t-statistic:

t = (xm - xf) / sqrt(Sp^2 * (1/nf + 1/nm))

xm = Male average weight (22.79 g)

xf = Female average weight (20.95 g)

Sp^2 (pooled variance) - calculated in step 2

4. Determine the p-value:

You'll need statistical software to find the p-value associated with the calculated t-statistic and the degrees of freedom (df = nf + nm - 2).

Statistical Measures:

t-statistic: This measures the difference between the means relative to the standard error of the sampling distribution. A positive value suggests the male mean is higher.

p-value: This represents the probability of observing a t-statistic as extreme or more extreme than the one calculated, assuming the null hypothesis is true.

A statistically significant p-value (typically less than 0.05) indicates we can reject the null hypothesis and conclude a difference between the means.

Based on the higher male average weight and large sample sizes, we expect a relatively large positive t-statistic and a statistically significant p-value (low p-value).

This would allow us to reject the null hypothesis (equal means) and conclude that male spotted flounder, on average, have a greater weight than females based on this data sample.

Which of these strategies can maximize insulation levels?
Use of vacuum-insulation panels
A. Adding rigid insulation outside of a stud wall to reduce thermal bridging
B. Increasing insulation thickness
C. Using spray-foam instead of batt insulation
D. Any of the above

Answers

Answer:

D. Any of the above

Explanation:

All of the following strategies maximize insulation levels:

Use of vacuum-insulation panels Adding rigid insulation outside of a stud wall to reduce thermal bridging Increasing insulation thickness Using spray-foam instead of batt insulation

A joining process in which a filler metal is melted and distributed by capillary action between faying surfaces, the base metals does not melt, and in which the filler metal melts at a temperature less than 450ᵉC is called?a.An arc welding processb. A soldering processc. An adhesive joining processd. A brazing processe. None of the above

Answers

Answer:

A soldering process

Explanation:

Given that ,The filler metal's melting point temperature is less than 450 ° C.

Usually, the brazing material has the liquid temperature of the melting point, the full melting point of the filler material approaching 450 degrees centigrade, while the filler material is less than 450 degrees centigrade in the case of soldering.

Therefore the answer is "A soldering process".

3. (20 points) Suppose we wish to search a linked list of length n, where each element contains a key k along with a hash value h(k). Each key is a long character string. How might we take advantage of the hash values when searching the list for an element with a given key?

Answers

Answer:

Alternatively we produce a complex (hash) value for key which mean that "to obtain a numerical value for every single string" that we are looking for.  Then compare that values along the range of list, that turns out be numerical values so that comparison becomes faster.

Explanation:

Every individual key is a big character  so to compare every keys, it is required to conduct a quite time consuming string reference procedure at every node. Alternatively we produce a complex (hash) value for key which mean that "to obtain a numerical value for every single string" that we are looking for.  Then compare that values along the range of list, that turns out be numerical values so that comparison becomes faster.

. Write a MATLAB program that calculates the arithmetic mean, the geometric mean, and the root-mean-square average for a given set of values. Your program must use 3 functions to calculate the 3 required means. The output should be formatted as follows:

Your name Statistical Package arithmetic mean = x.xxxxx geometric mean = x.xxxxx RMS average = x.xxxxx

Test your program on the following values: 1.1, 3.3, 3.00, 2.22, 2.00, 2.72, 4.00, 4.62 and 5.37. Your main program calls 3 functions.

The data should be read by the main program from a text file, stored in an array and then passed to the functions.

The results and any other output should be printed by the main program. Notice how the output results are aligned. Also notice that the results are printed accurate to 5 decimal places.

DO NOT USE MATLAB BUILT-IN FUNCTIONS.

Answers

Answer:

Mean.m

fid = fopen('input.txt');

Array = fscanf(fid, '%g');

Amean = AM(Array);

Gmean = GM(Array);

Rmean = RMS(Array);

display('Amlan Das Statistical Package')

display(['arithmetic mean = ', sprintf('%.5f',Amean)]);

disp(['geometric mean = ', sprintf('%.5f',Gmean)]);

disp(['RMS average = ', sprintf('%.5f',Rmean)]);

AM.m

function [ AMean ] = AM( Array )

n = length(Array);

AMean = 0;

for i = 1:n

AMean = AMean + Array(i);

end

AMean = AMean/n;

end

GM.m

function [ GMean ] = GM(Array)

n = length(Array);

GMean = 1;

for i = 1:n

GMean = GMean*Array(i);

end

GMean = GMean^(1/n);

end

RMS.m

function [ RMean ] = RMS( Array)

n = length(Array);

RMean = 0;

for i = 1:n

RMean = RMean + Array(i)^2;

end

RMean = (RMean/n)^(0.5);

end

Water at 120oC boils inside a channel with a flat surface measuring 45 cm x 45 cm. Air at 62 m/s and 20oC flows over the channel parallel to the surface. Determine the heat transfer rate to the air. Neglect wall thermal resistance.

Answers

Answer:

Q = 2.532 x 10³ W

Explanation:

The properties of air at the film temperature of

T(f) = (T(s) + T()∞)/2

T(f) = (120 + 20)/2 = 70 °C

From the table of properties of air at T = 20 °C we know that ρ = 1.028 kg/m³ , k = 0.02881W/mK, Pr = 0.7177 , v = 1.995 x 10⁻⁵ m²/s

Calculate the Reynold’s Number

Re(l) = V x L/ν, where V is the speed of air flowing, L is the length of the surface in meters and ν is the kinematic viscosity

Re(l) = 62 x 0.45/(1.995 x 10⁻⁵) = 1.398 x 10⁶

Re(l) is greater than the critical Reynold Number. Thus, we have combined laminar and turbulent flow and the average Nusselt number for the entire plate is determined by

Nu = (0.037 x (Re(l)^0.8) - 871) x Pr^1/3, where Pr is the Prandtl’s Number

Nu = (0.037 x (1.398 x 10⁶)^0.8) – 871) x (0.7177)^1/3

Nu = 1952.85

We also know that

Nu = h x L/k, where h is the heat transfer coefficient, L is the length of the surface and  k is the thermal conductivity

Rearranging to solve for h

h = (Nu x k)/l

h = 1952.85 x 0.02881/0.45 = 125.03 W/m²C

The heat transfer rate Q, may be determined by

Q = h x A x (T(s) - T(∞))

Q = 125.03 x 0.45 x 0.45 x (120 - 20)

Q = 2.532 x 10³ W

The heat transfer rate is 2.532 x 10³ W to the air.

Problem 5) Water is pumped through a 60 m long, 0.3 m diameter pipe from a lower reservoir to a higher reservoir whose surface is 10 m above the lower one. The sum of the minor loss coefficient for the system is kL = 14.5. When the pump adds 40 kW to the water, the flow rate is 0.2 m3/s. Determine the pipe roughness.

Answers

Answer:

\epsilon = 0.028*0.3 = 0.0084

Explanation:

\frac{P_1}{\rho} + \frac{v_1^2}{2g} +z_1 +h_p - h_l =\frac{P_2}{\rho} + \frac{v_2^2}{2g} +z_2

where P_1 = P_2 = 0

V1 AND V2  =0

Z1 =0

h_P = \frac{w_p}{\rho Q}

=\frac{40}{9.8*10^3*0.2} = 20.4 m

20.4 - (f [\frac{l}{d}] +kl) \frac{v_1^2}{2g} = 10

we know thaTV  =\frac{Q}{A}

V = \frac{0.2}{\pi \frac{0.3^2}{4}} =2.82 m/sec

20.4 - (f \frac{60}{0.3} +14.5) \frac{2.82^2}{2*9.81} = 10

f  = 0.0560

Re =\frac{\rho v D}{\mu}

Re =\frac{10^2*2.82*0.3}{1.12*10^{-3}} =7.53*10^5

fro Re = 7.53*10^5 and f = 0.0560

\frac{\epsilon}{D] = 0.028

\epsilon = 0.028*0.3 = 0.0084

A 20 mm 3 20 mm silicon chip is mounted such thatthe edges are flush in a substrate. The substrate provides anunheated starting length of 20 mm that acts as turbulator. Airflow at 25°C (1 atm) with a velocity of 25 m/s is used to coolthe upper surface of the chip. If the maximum surface temperature of the chip cannot exceed 75°C, determine the maximumallowable power dissipation on the chip surface.

Answers

Answer:

q= 1.77 W

Explanation:

Given data, Dimensions = 20mm x 20mm, Unheated starting length (ε) = 20 mm, Air flow temperature = 25 C, Velocity of flow = 25m/s, Surface Temperature = 75 C

To find maximum allowed power dissipated use the formula Q = hA(ΔT), where Q = Maximum allowed power dissipated from surface , h = heat transfer coefficiant, A = Area of Surface, ΔT = Temperature difference between surface and surrounding

we need to find h, which is given by (Nu x K)/x, where Nu is the Nusselt's Number, k is the thermal conductivity at film temperature and x is the length of the substrate.

For Nu use the Churchill and Ozoe relation used for parallel flow over the flat plate , Nu = (Nux (ε=0))/[1-(ε/x)^3/4]^1/3

Nux (ε=0) = 0.453 x Re^0.5 x Pr^1/3, where Re is the Reynolds number calculated by [Rex = Vx/v, where V is the velocity and v is the kinematic velocity, x being the length of the substrate] and Pr being the Prandtl Number

The constants, namel Pr, k and v are temperature dependent, so we need to find the film temperature

Tfilm = (Tsubstrate + Tmax)/2 = (25 + 75)/2 = 50 C

At 50 C, Pr = 0.7228, k = 0.02735w/m.k , v = 1.798 x 10^-5 m2/s

First find Rex and keep using the value in the subsequent formulas until we reach Q

Rex = Vx/v = 25 x (0.02 + 0.02)/ 1.798 x 10^-5  = 55617.35 < 5 x 10^5, thus flow is laminar, (x = L + ε)

Nux = (Nux (ε=0))/[1-(ε/x)^3/4]^1/3 = 0.453 x Re^0.5 x Pr^1/3/[1-(ε/x)^3/4]^1/3

= 0.453 x 55617.35 ^0.5 x 0.7228^1/3/ [1 - (0.02/0.04)^3/4]^1/3 = 129.54

h = (Nu x K)/x = (129.54 x 0.02735)/0.04 = 88.75W/m2.k

Q = 88.75 x (0.02)^2 x (75-25) = 1.77 W

Write a program that counts the number of bits equal to one in R1, and stores the result in R2. For example, if R1=x0A0C, then R2=x0004 after the program runs. To receive credit, you can only modify the contents of R1 and R2, and no other register, and your solution should have no more than 9 lines of code.

Answers

Answer:

MOV R1, $0A0C    ;

  MOV R2, #0 ;

L1 : MOV R1, R1, LSL #1 ;

  ADC R2, R2, #1 ;

  CMP R1, #0 ;

  BNE L1    ;

How many of the following statements are correct regarding the buckling of slender members?
(i) Buckling occurs in axially loaded members in tension;
(ii) Buckling is caused by the lateral deflection of the members;
(iii) Buckling is an instability phenomenon.

Answers

Answer:

False, True , True.

Explanation:

Buckling is defined as  large lateral deflection of member of under compression with slight increase in load beyond a critical load.  

1) Buckling occurs in axially loaded member in tension. is false as buckling occurs in tension.

2) Buckling is caused by lateral deflection of the member and not the axial  deflection. hence true.

3) Buckling is an instability phenomenon that can lead to failure. Hence True.

Write a function digits() that accepts a non-negative integer argument n and returns the number of digits in it’s decimal representation. For credit, you should implement this using a loop and repeated integer division; you should not use math.log(), math.log10(), or conversion to string

Answers

Answer:

Explanation:

Let do this in python. We will utilize the while loop and keep on dividing by 10 until that number is less than 10. Along the loop we will count the number of looping process. Once the loop ends, we can output that as answer.

def digits(n):

    n_digit = 1

    while n >= 10:

         n_digit += 1

         n /= 10

    return n_digit

// This program is supposed to display every fifth year // starting with 2017; that is, 2017, 2022, 2027, 2032, // and so on, for 30 years. start Declarations num year num START_YEAR = 2017 num FACTOR = 5 num END_YEAR = 30 year = START_YEAR while year <= END_YEAR output year endif stop 1. What problems do you see in this logic? 2. Show corrected pseudocode to fix the problems. 3. Is there another way the code can be corrected and still have the same outcome? If so, please describe. 4. Implement your pseudocode in either Raptor or VBA. (submit this file) 5. Does it work? You must test your code before submitting and indicate if the program functions according to the assignment description. Explain.

Answers

Answer:

Explanation:

1. The problems in the above pseudocode include (but not limited to) the following

1. The end year is not properly represented.

2. Though, the factor of 5 is declared, it's not implemented as increment in the pseudocode

3. Incorrect use of control structures. (While ...... And .......Endif)

2.

Start

Start_Year = 2017

Kount = 1

While Kount <= 30

Display Start_Year

Start_Year = Start_Year + 5

Kount = Kount + 1

End While

Stop

3. Yes, by doing the following

* Apply increment of 5 to start year within the whole loop, where necessary

* Use matching control structures

While statement ends with End While (not end if, as it is in the question)

4. Using VBA

Dim Start_Year: Start_Year = 2017 ' Declare and initialise year to 2017

Dim Counter: Counter = 1 ' Declare and Initialise Counter to 1

While Count <= 30 ' Test Value of Counter; to check if the desired number of year has gotten to 30. While the condition remains value, the following code will be executed.

msgbox Start_Year ' Display the value of start year

Start_Year = Start_Year + 5 'Increase value of start year by a factor of 5

Counter = Counter + 1 'Increment Counter

Wend

5. Yes

Write a program that stores lists of names (the last name first) and ages in parallel arrays and sorts the names into alphabetical order keeping the ages with the correct names. The original arrays of names and ages should remain no changes. Therefore, you need to create an array of character pointers to store the addresses of the names in the name array initially. Apply the selection sort to this array of pointers so that the corresponding names are in alphabetical order.

Answers

Answer:

#include <stdio.h>

#include <string.h>

#include <stdlib.h>

#define STRSIZ 30

#define MAXAPP 50

int alpha_first(char *list[], int min_sub, int max_sub);

void select_sort_str(char *list[], int * numbers[], int n);

int main()

{

   char applicants[MAXAPP][STRSIZ];

   int ages[MAXAPP];

 

   char* alpha[MAXAPP];

   int* numeric[MAXAPP];

   int num_app, i, j;

   char one_char;

   printf("Enter number of people (0 . . %d)\n> ", MAXAPP);

   scanf("%d", &num_app);

 

   for (i = 0; i < num_app; i++)

   {

   

       scanf("%c", &one_char);

       printf("\nEnter name %d (lastname, firstname): ", i + 1);      

       j = 0;

       while ((one_char = (char)getchar()) != '\n' && j < STRSIZ)

           applicants[i][j++] = one_char;

       applicants[i][j] = '\0';

 

       printf("Enter age %d: ", (i + 1));

       scanf("%d", &ages[i]);

       alpha[i] = (char*)malloc(strlen(applicants[i]) * sizeof(char));

       strcpy(alpha[i], applicants[i]);

       numeric[i] = &ages[i];

   }

   printf("\n\nOriginal list");

   printf("\n---------------------------\n");

   for (i = 0; i < num_app; ++i)

       printf("%-30s%2d\n", applicants[i], ages[i]);

   select_sort_str(alpha, numeric, num_app);

   printf("\n\nAlphabetized list");

   printf("\n---------------------------\n");

   for (i = 0; i < num_app; ++i)

       printf("%-30s%2d\n", alpha[i], *numeric[i]);

   printf("\n\nOriginal list");

   printf("\n---------------------------\n");

   for (i = 0; i < num_app; ++i)

       printf("%-30s%2d\n", applicants[i], ages[i]);

   return 0;

}

int alpha_first(char* list[], int min_sub, int max_sub)

{

   int first, i;

   first = min_sub;

   for (i = min_sub + 1; i <= max_sub; ++i)

       if (strcmp(list[i], list[first]) < 0)

           first = i;

   return (first);

}

void select_sort_str(char* list[], int* numbers[], int n)

{

   int fill, index_of_min;

   char* temp;

   int* tempNum;

   for (fill = 0; fill < n - 1; ++fill)

   {

   

       index_of_min = alpha_first(list, fill, n - 1);

       if (index_of_min != fill)

       {

       

           temp = (char*)malloc(strlen(list[fill]) * sizeof(char));

           strcpy(temp, list[index_of_min]);

           strcpy(list[index_of_min], list[fill]);

           strcpy(list[fill], temp);

     

           tempNum = numbers[index_of_min];

           numbers[index_of_min] = numbers[fill];

           numbers[fill] = tempNum;

       }

   }

}

Ammonia enters an adiabatic compressor operating at steady state as saturated vapor at 300 kPa and exits at 1400 kPa, 140◦C. Kinetic and potential energy effects are negligible. Determine:
a. power input required [kJ/kg]
b. isentropic compressor efficiency
c. rate of entropy production per unit mass [kJ/kg K] in the compressor

Answers

Answer:

a. 149.74 KJ/KG

b. 97.9%

c. 0.81 kJ/kg K

Explanation:

22.5-4. Minimum Liquid Flow in a Packed Tower. The gas stream from a chemical reactor contains 25 mol % ammonia and the rest are inert gases. The total flow is 181.4 kg mol/h to an absorption tower at 303 K and 1.013 × 105 Pa pressure, where water containing 0.005 mol frac ammonia is the scrubbing liquid. The outlet gas concentration is to be 2.0 mol % ammonia. What is the minimum flow L min ⁡ ′ Using 1.5 times the minimum, plot the equilibrium and operating lines. Ans. L min ⁡ ′ = 262.6kg mol/h

Answers

Answer:

check attachments for answers

Explanation:

For the unity negative feedback system G(s) = K(s+6)/ (s + 1)(s + 2)(s + 5) It's known that the system is operating with a dominant-pole damping ratio of 0.5. Design a PD controller so that the settling time is reduced by a factor of 3, compared with the uncompensated unity negative feedback system. Compare the percentage overshoot and resonant frequencies of the uncompensated and compensated systems.

Answers

Answer:The awnser is 5

Explanation:Just divide all of it

A window-mounted air conditioner supplies 29 m3/min of air at 15°C, 1 bar to a room. Air returns from the room to the evaporator of the unit at 22°C. The air conditioner operates at steady state on a vapor-compression refrigeration cycle with Refrigerant 22 entering the compressor at 4 bar, 10°C. Saturated liquid refrigerant at 14 bar leaves the condenser. The compressor has an isentropic efficiency of 70%, and refrigerant exits the compressor at 14 bar.
Determine the compressor power, in KW, the refrigeration capacity, in tons, and the coefficient of performance.

Answers

Answer:

Please see explanation below .

Explanation:

Since you have not provided the db schema, I am providing the queries by guessing the table and column names. Feel free to reach out in case of any concerns.

1. SELECT ISBN, TITLE, PUBLICATION_YEAR FROM BOOKS WHERE AUTHOR_ID = (SELECT AUTHOR_ID FROM AUTHOR WHERE AUTHOR_NAME = 'C.J. Cherryh');

2. SELECT COUNT(*) FROM BOOKS;

3. SELECT COUNT(*) FROM ORDERS WHERE CUSTOMER_ID = 11 AND order_filled = 'No';

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