Answer:
Ts = 413.66 K
Explanation:
given data
temperature = 20°C
velocity = 10 m/s
diameter = 5 mm
surface emissivity = 0.95
surrounding temperature = 20°C
heat flux dissipated = 17000 W/m²
to find out
surface temperature
solution
we know that here properties of air at 70°C
k = 0.02881 W/m.K
v = 1.995 ×
m²/s
Pr = 0.7177
we find here reynolds no for air flow that is
Re = 
Re = 
Re = 2506
now we use churchill and bernstein relation for nusselt no
Nu = 
= 0.3 + ![\frac{0.62 Re6{0.5}Pr^{0.33}}{[1+(0.4/Pr)^{2/3}]^{1/4}} [1+ (\frac{2506}{282000})^{5/8}]^{4/5}](https://tex.z-dn.net/?f=%5Cfrac%7B0.62%20Re6%7B0.5%7DPr%5E%7B0.33%7D%7D%7B%5B1%2B%280.4%2FPr%29%5E%7B2%2F3%7D%5D%5E%7B1%2F4%7D%7D%20%5B1%2B%20%28%5Cfrac%7B2506%7D%7B282000%7D%29%5E%7B5%2F8%7D%5D%5E%7B4%2F5%7D)
h = 
0.3 + ![\frac{0.62*2506{0.5}0.7177^{0.33}}{[1+(0.4/0.7177)^{2/3}]^{1/4}} [1+ (\frac{2506}{282000})^{5/8}]^{4/5}](https://tex.z-dn.net/?f=%5Cfrac%7B0.62%2A2506%7B0.5%7D0.7177%5E%7B0.33%7D%7D%7B%5B1%2B%280.4%2F0.7177%29%5E%7B2%2F3%7D%5D%5E%7B1%2F4%7D%7D%20%5B1%2B%20%28%5Cfrac%7B2506%7D%7B282000%7D%29%5E%7B5%2F8%7D%5D%5E%7B4%2F5%7D)
h = 148.3 W/m².K
so
q conv = h∈(Ts- T∞ )
17000 = 148.3 ( 0.95) ( Ts - (20 + 273 ))
Ts = 413.66 K
Answer:
5
Explanation:
The sum of the digits of the number is ...
(4+1+3)+(4+6+5)+(7+8+9) = 8+15+24 = 47
The sum of those digits is 4+7=11, and those digits sum to 1+1 = 2.
That is, the value of the number mod 9 (or 3) is 2.
The ones digit is odd, so the value of the number mod 2 is 1.
This combination of modulo values tells you the mod 6 result is 5.
_____
<em>Additional comment</em>
We can look at the (mod2, mod3) values of the numbers 0 to 5:
0 ⇒ (0, 0)
1 ⇒ (1, 1)
2 ⇒ (0, 2)
3 ⇒ (1, 0)
4 ⇒ (0, 1)
5 ⇒ (1, 2) . . . . the mod {2, 3} results we have for the number of interest.
This process of adding up the digits repeatedly is referred to as "casting out 9s." The result of it is the modulo 9 value of the number (with 0 mapped to 9). Checking the mod 9 result of arithmetic operations is one quick way to spot certain kinds of errors. It can also be used as part of a divisibility test for 3 or 9.
I think the orange thing on the gun but i dont know what principle it is but i think its c
Explanation:
Whem you press the orange thing it starts to work
Answer:
The solution code is given below
- using System;
- using System.Linq;
-
- public class Program
- {
- public static void Main()
- {
- string[] letters = {"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T","U", "V", "W", "X", "Y", "Z"};
-
- Console.WriteLine("Please input a letter: ");
- string input_letter = Console.ReadLine();
-
- if(letters.Contains(input_letter)){
- Console.WriteLine("OK");
- }else{
- Console.WriteLine("Error. Not uppercase letter.");
- }
- }
- }
Explanation:
Firstly we import the necessary libraries, System and Linq (Line 1-2).
Next we create a string array to hold all uppercase letters (Line 8).
Next, we prompt user to input a letter using the ReadLine() method (Line 10 - 11)
At last, we define if and else conditions to check if the letters contains the input letter. If so, print ok else print an error message. (Line 13-17)
Answer:
Engineering
Explanation:
STEM mainly incorporate knowledge from four disciplines which are:
- Science
- Technology
- Engineering
- Mathematics
The field of engineering combines concepts mainly from Science and Mathematics then with the help of technological developments using software, engineering field designs various structures and other elements that are essential to humanity.
Keywords: STEM, Science
, Technology
, Engineering
, Mathematics
