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Romashka-Z-Leto [24]
2 years ago
9

Single-use earplugs require a professional fitting before they can be used.

Engineering
1 answer:
Musya8 [376]2 years ago
8 0
What are you asking? are you asking if it is true or false? sorry :(( i can help you tho!
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1. A cylindrical casting is 0.3 m in diameter and 0.5 m in length. Another casting has the same metal is rectangular in cross-se
Lorico [155]

Based on the Chvorinov's rule, the diference in the <em>solidification</em> times of the two castings is 14.092 times the <em>solidification</em> time of the prism casting.

<h3>How to apply the Chvorinov's rule for casting processes</h3>

The Chvorinov's rule is an empirical method to estimate the cooling time of a casting in terms of a <em>reference</em> time. This rule states that cooling time (<em>t</em>) is directly proportional to the square of the volume (<em>V</em>), in cubic meters, divided to the surface area (<em>A</em>), in square meters. Now we proceed to model each casting:

<h3>Cylindrical casting</h3>

t = C · [0.25π · D² · L/(0.5π · D² + π · D · L)]²

t = C · [0.25 · D · L/(0.5 · D + L)]²    (1)

<h3>Prism casting</h3>

t' = C · [3 · T² · L/(6 · T · L + 2 · T · L + 6 · T²)]²

t' = C · [3 · T · L/(8 · L + 6 · T)]²     (2)

<h3>Relationship between the cross sections of both castings</h3>

3 · T² = 0.25π · D²     (3)

Where:

  • <em>t</em> - Cooling time of the cylindrical casting, in time unit.
  • <em>t'</em> - Cooling time of the prism casting, in time unit.
  • <em>C</em> - Cooling factor, in time unit per square meter.
  • <em>D</em> - Diameter of the cylinder, in meters.
  • <em>L</em> - Length of the casting, in meters.
  • <em>T</em> - Width of the cross section of the prism casting, in meters.

If we know that <em>D =</em> <em>0.3 m</em>, then the thickness of the prism casting is:

T = \sqrt{\frac{\pi}{12} }\cdot D

<em>T ≈ 0.153 m</em>

<em />

And (1) and (2) simplified into these forms:

<h3>Cylindrical casting</h3>

t = C · {0.25π · (0.3 m) · (0.5 m)/[0.5 · (0.3 m) + 0.5 m]}²

t = 0.0329 · C     (1b)

<h3>Prism casting</h3>

t' = C · {3 · (0.153 m) · (0.5 m)/[8 · (0.5 m) + 6 · (0.153 m)]}²

t' = 0.00218 · C     (2b)

Lastly we find the <em>percentual</em> difference in the solidification times of the two castings by using the following expression:

<em>r = (</em>1 <em>- t'/t) ×</em> 100 %

<em>r = (</em>1 <em>-</em> 0.00218<em>/</em>0.0329<em>) ×</em> 100 %

<em>r =</em> 93.374 %

The <em>cooling</em> time of the <em>prism</em> casting is 6.626 % of the <em>solidification</em> time of the <em>cylindrical</em> casting. The diference in the <em>solidification</em> times of the two castings is 14.092 times the <em>solidification</em> time of the <em>prism</em> casting. \blacksquare

To learn more on solidification times, we kindly invite to check this verified question: brainly.com/question/13536247

3 0
2 years ago
Which symbol should be used for the given scenario?
Firdavs [7]

Answer:

speed square

Explanation:

4 0
2 years ago
Im passed due someone help meeeeeee
vovangra [49]

Answer:

how are supposed to help when you can't do anything?

8 0
3 years ago
Read 2 more answers
Driving Distraction Brainstorming Session
Leto [7]

texting, phone calls, putting on makeup, brushing hair, movies playing in car, loud music, children, and that's pretty much all I could think of

please give <u>BRAINLIEST ANSWER └[T‸T]┘</u>

5 0
3 years ago
Bob and Alice are solving practice problems for CSE 2320. They look at this code: for(i = 1; i &lt;= N; i = (i*2)+17 ) for(k = i
MissTica

Answer:

Alice is correct.

The loop are dependent.

Explanation:

for(i = 1; i <= N; i = (i*2)+17 )

for(k = i+1; k <= i+N; k = k+1) // notice i in i+1 and i+N

printf("B")

This is a nested for-loop.

After the first for-loop opening, there is no block of statement to be executed rather a for-loop is called again. And the second for-loop uses the value of i from the first for-loop. The value of N is both called from outside the loop.

So, the second for-loop depend on the first for loop to get the value of i. For clarity purpose, code indentation or use of curly brace is advised.

8 0
3 years ago
Read 2 more answers
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