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Ronch [10]
3 years ago
8

A hypothetical metal alloy has a grain diameter of 1.7 102 mm. After a heat treatment at 450C for 250 min, the grain diameter ha

s increased to 4.5 102 mm. Compute the time required for a specimen of this same material (i.e., d 0 1.7 102 mm) to achieve a grain diameter of 8.7 102 mm while being heated at 450C. Assume the n grain diameter exponent has a value of 2.1.
Engineering
1 answer:
Romashka-Z-Leto [24]3 years ago
4 0

Answer:

the required time for the specimen is  1109.4 min

Explanation:

Given that;

diameter of metal alloy d₀ = 1.7 × 10² mm

Temperature of heat treatment T = 450°C = 450 + 273 = 723 K

Time period of heat treatment t = 250 min

Increased grain diameter 4.5 × 10² mm

grain diameter exponent n = 2.1

First we calculate the time independent constant K

dⁿ - d₀ⁿ = Kt

K = (dⁿ - d₀ⁿ) / t

we substitute

K = (( 4.5 × 10² )²'¹ - ( 1.7 × 10² )²'¹) / 250

K = (373032.163378 - 48299.511117) / 250

K = 1298.9306 mm²/min

Now, we calculate the time required for the specimen to achieve the given grain diameter ( 8.7 × 10² mm )

dⁿ - d₀ⁿ = Kt

t = (dⁿ - d₀ⁿ) / K

t = (( 8.7 × 10² )²'¹ - ( 1.7 × 10² )²'¹) / 1298.9306

t = ( 1489328.26061158 - 48299.511117) / 1298.9306

t = 1441028.74949458 / 1298.9306

t = 1109.4 min

Therefore, the required time for the specimen is  1109.4 min

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nordsb [41]

Answer:

Program code is given below.

Explanation:

#include <iostream>

using namespace std;03

int main()

{

char neutered, opselect, animal;

const int dogcost = 80, catcost = 60, birdOrReptilecost = 0;

cout << "What kind of animal do you have?\n";

cout << "d for dog, c for cat, b for bird or reptile and o for others.\n\n";

cin >> animal;

cout << "Answer the following questions\n";

cout << "With Y for yes or N for no.\n\n";

cout << "Is your pet neutered? ";

cin >> neutered;

cout << "Enter a select code: ";

cout << "\n1)A dog that has been neutered: ";

cout << "\n2)A dog that has not been neutered: ";

cout << "\n3)A cat that has been neutered costs: ";

cout << "\n4)A cat that has not been neutered costs: ";

cout << "\n5)A bird or reptile: ";

cin >> opselect;

switch (opselect)

{

  case 1:

    cout << "The price for dog that has been neutered is " << dogcost - 30;

    break;

  case 2:

    cout << "The price for dog that has not been neutered is " << dogcost << endl;

   break;

  case 3:

    cout << "The price for cat that has been neutered is " << catcost - 20 << endl;

   break

  case 4:

    cout << "The price for cat that has not been neutered is " << catcost << endl;

   break;

  case 5:

    cout << "The price for bird or reptile is " << birdOrReptilecost << endl;

break;

return 0;

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4 0
3 years ago
Researcher Timothy Salthouse suggests that if people are mentally active all of their lives, they enter late adulthood with ____
mylen [45]

Answer:

Researcher Timothy Salthouse proposes that if the person is mentally active throughout their lives, they will have a cognitive reserve in late adulthood that will help them continue to execute a high mental level.

Explanation:

The psychologist Timothy Salthouse focused his research on cognitive aging, and his study is considered very important in the area since it helped identify the first signs of cognitive impairment.

The psychologist Salthouse considered that if the person had an excellent cognitive reserve would not be strongly affected by the brain deterioration that occurs over the years.  

The cognitive reserve is the competition that the brain has to balance the deterioration that occurs over the years in people. This cognitive reserve is related to the actions that the brain performed previously, habits, and knowledge acquired by the person over time.

Therefore, older adults who have taken actions to strengthen their cognitive processing will have better advantages in obtaining the cognitive reserve.

<em>I hope this information can help you.</em>

5 0
4 years ago
Rocks in mountains can be weathered by breaking them apart. How can they be eroded?
Ksju [112]

Answer: If you look up its definition of eroded it'll tell you the answer should be B

Explanation:

5 0
3 years ago
A cooling system load is 96,000 BTUh sensible. How much chilled air is required to satisfy the load if the system is designed fo
Natalija [7]

Answer:

For 20^{\circ} - 5.556 lb/s

For 15^{\circ} - 7.4047 lb/s

Solution:

As per the question:

System Load = 96000 Btuh

Temperature, T = 20^{\circ}

Temperature rise, T' = 15^{\circ}

Now,

The system load is taken to be at constant pressure, then:

Specific heat of air, C_{p} = 0.24 btu/lb ^{\circ}F

Now, for a rise of 20^{\circ} in temeprature:

\dot{m}C_{p}\Delta T = 96000

\dot{m} = \frac{96000}{C_{p}\Delta T} = \frac{96000}{0.24\times 20} = 20000 lb/h = \frac{20000}{3600} = 5.556 lb/s

Now, for 15^{\circ}:

\dot{m}C_{p}\Delta T = 96000

\dot{m} = \frac{96000}{C_{p}\Delta T} = \frac{96000}{0.24\times 15} = 26666.667 lb/h = \frac{26666.667}{3600} = 7.4074 lb/s

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3 years ago
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GenaCL600 [577]

Answer:

True

Explanation:

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