Chapter 21 Computer CaseLila Lovetree was examining the latest electric bill for her store AIl Organics" Even though was November; the bill was still $1,200.00...

Your next-door neighbor, Josephine Rackstraw, surprised her husband last January by having a hot tub installed in their back yard while he was away on an ice-fishing trip. It surprised him, all right, but instead of being pleased he was horrified. "Have you lost your mind, Josephine?" he sputtered. "It will cost a fortune to keep this thing hot, and you know what the President said about conserving energy." "Don't be silly, Ralph," she replied. "It can't cost more than a few pennies a day, even in the dead of winter." "No way -just because you have a PhD, you think you're an expert on everything!" They argued for a while, bringing up several issues that each had been storing for just such an occasion. After calming down and using the tub for a week, they remembered their neighbor (i.e., you) had a chemical engineering education and came to ask if you could settle their argument. You asked a few questions, made several observations, converted everything to metric units, and arrived at the following data, all corresponding to an average outside temperature of $5^{\circ} \mathrm{C}$. - The tub holds 1230 liters of water. - Ralph normally keeps the tub temperature at $29^{\circ} \mathrm{C}$, raises it to $40^{\circ} \mathrm{C}$ when he plans to use it, keeps it at $40^{\circ} \mathrm{C}$ for about one hour, and drops it back to $29^{\circ} \mathrm{C}$ when he is finished. - During heating, it takes about three hours for the water temperature to rise from $29^{\circ} \mathrm{C}$ to $40^{\circ} \mathrm{C}$. When the heat is shut off, it takes eight hours for the water temperature to drop back to $29^{\circ} \mathrm{C}$. - Electricity costs 10 cents per kilowatt-hour. Taking the heat capacity of the tub contents to be that of pure liquid water and neglecting evaporation, answer the following questions. (a) What is the average rate of heat loss ( $k W$ ) from the tub to the outside air? (Hint: Consider the period when the tub temperature is dropping from $40^{\circ} \mathrm{C}$ to $29^{\circ} \mathrm{C}$.) (b) At what average rate ( $\mathrm{kW}$ ) does the tub heater deliver energy to the water when raising the water temperature? What is the total quantity of electricity (kW\cdoth) that the heater must deliver during this period? [Consider the result of Part (a) when performing the calculation.] (c) (These answers should settle the argument.) Consider a day in which the tub is used once. Use the results of Parts (a) and (b) to estimate the cost (S) of heating the tub from $29^{\circ} \mathrm{C}$ to $40^{\circ} \mathrm{C}$ and the cost $(\mathrm{S})$ of keeping the tub at a constant temperature. (There is no cost for the period in which $T$ is dropping.) What is the total daily cost of running the tub? Assume the rate of heat loss is independent of the tub temperature. (d) The tub lid, which is an insulator, is removed when the tub is in use. Explain how this fact would probably affect your cost estimates in Part (c).

So this question wants us to consider each other full situation for undersea forklifts. I just dropped a with that shows the situation the responsibility to the country of liberty on the suggestion for the problems. So the first question is in the manufacturing plant. The production manager is not happy with the engines that the purchasing manager has been purchasing. In May, the production manager stops requesting engines from the supply Wales on starts, processing them directly from a different engine manufacturer. Actual materials caused in me. I had them budgeted. Not for this question. It's situation one on into it. It is the responsibility off the production manager on it is the controllability of the porch Izzy manager. Now for the suggestions, I would suggest that the production manager should consult purchasing manager for purchasing monitors property in the models on. In order to improve the situation, the producer of the production manager should order quality and efficient models, which satisfied the requirements off the production off the production managers. So judicial managers shoot, consult what cheesy manages on other quality on efficient social, the quality and efficient forklifts. Now, the second question overhead costs in the manufacturing plants for June are much higher than budgeted. Investigation. We feel that a utility rate with Ike and the effect that was not figured into the market into the budget. Rather, so this is situation through on it is the responsibility off the production manager still, and it's also the country, the beauty of the production manager on for the suggestion. In order to service situation, the production manager should collect all the information I relevant like the I like the utility rates. Onda should figure out to figure it out into the budget, so must collect all relevant. I figure it out into the budget, and that's for that. Yeah, now the next question. No. About three, this one says Gasoline costs for each van are budgeted based on the service area off the van on the amount of driving expected for the month now the Java or 13 recently as monthly as monthly gasoline costs exceeding the budget off the van except in the budget for 13 After investigating, the service manager finds out that the driver has been driving the one for personal use. Now it's very responsibility off the driver driver over three. I am the controllability of the service manager. Now you know that's to control the cost. The service manager should constantly check the kilometers at the beginning and ending of the date on daily basis. And service manager should also compared Istana kilometer on actual kilometer driven. So the service manager should check the kilometer. Adds the beginning. On end of the day, I compared the standard he limited with actual kilometers. It's actual kilometers driven. Okay, that's that. Not number four situation for this one says that's big store. Where else? One of understands for Cliff Service customers, the service people are on Lee. The service people are only called for in called in for emergencies are not for routine. Maintain us. So tell us the materials and label cost for this service calls exceeds the monthly budget it'll cost for a contract manager. Now for this, it's for this situation. It's the responsibility off. They maintain a spa by so on. It is the controllability off this service manager now to continue to to solve this situation. Controlling the material and labor costs will lead to a better improvement, so we need to control the material and labor costs that's for that questions. No situation. Five On the Saints service technicians are paid hourly wage. It's overtime pay if they exceed 40 hours a week, excluding driving time. First nurse. One of the technicians frequently exceeds 40 hours a week. Right service customers are happy with Fred Fred's work, but the service manager talks to him constantly about working more quickly. Now, afraid over time causes the actual cost off service to exceed the project almost every month. Now for this, it is the responsibility of the technician, Fred. Right? So technician, honestly, the controllability of the service manager not for to control the situation. The service manager should motivates the technician to finish his trucks. You know, within the given time is giving on should not exceed 40 hours a week. So service manager should motivates the technician. So finish is tux. We didn't be given time. That's the answer. None of about 60 lakhs situation. The cost of gasoline has increased by 50% this year, right, which caused the actual gasoline cost to greatly exceed the budget. A cost for the service vans now for For this situation, the responsibility is for the purchasing managers on the controllability is for the production manager. Mhm, mhm, mhm and so control situation production manager, all right at the purchasing manager should must be aware of the market conditions and should make advance purchases, you know, to avoid lost when the price increases. So the what Chasing mom ninjas must be aware off markets conditions ahead. I make advance purchases, so avoid loss when prices increases, and that's that's the so bad situation.

Caution number 86. The last question off the chapter on the longest. We'll start with the basics. The definition off standard Intel pecan can compassion is the Intel API change for one more off substance that bones or combines with the oxygen under standard state condition. That is one more pressure and 2 98 Calvin and preacher for but a assuming that the natural gas is pure meeting meeting. Therefore, the heat provided is 3500 kilowatt with 89% fullness. Efficiency deter mining the amount off heat provided by meeting in Tokyo. Jules, we can calculate it has 1.26 into 10 days to pass seven kilo Jules. But as the efficiency off gas furnace is the percent off heat produced by the commotion that is transferred into the house, therefore it is decreased to 1.42 into 10 days to par seven. Colonials, therefore, calculating the number off moles off meeting required to produce this amount off heat, we can refer to the table for standard heat compassion provided into the textbook that is negative off 890.8 killa jewels, so the number off meeting required would be 15,940 moves. Okay, that's quite tight. After calculating the number of moves off meeting, the total mass off meeting can be calculated substituting in the values off. Okay, we can calculate the number off moles that is mass by motor miles, So the total mass off meeting turns out to be 255700 Graham. That's a lot. No substituting in the value off density off meeting on the mask off meeting being calculate the volume off meeting in leaders that turns out to be 375 500 leaders. We can convert the above volume off, meeting in leaders in tow, cubic feet using this correlation. So the volume in cubic feet turns out to be 13,260 cubic feet for part B, as the heat produced by compassion off gas that is transferred into the house is already calculated, which is one point for doing to tend to surpass seven, Kill a Jew. Assuming that the LPD is liquid propane, we can again refer to the table, and we can have the heat off condition that turns out to be 2219. Killer trooper move As the last time we can calculate the number off Moulds were stoned. That Toby 6399 moods substituting in the values off Moeller Mass. On number off moves off propane into the given equation, which is represented Over here, we can calculate the total mass of propane required. That turns out to be 28,200 grounds using the density mass relation, which is represented by the equation. Over here, we can calculate the total volume that turns out to be 53.7 leaders. We can't own that leader in tow. The gallons. It's through this correlation. It turns out to be 100 and 41.2 gallons, considering the falling reaction off meeting, which leads to Formacion off to mood off water and one more off carbon dioxide, According to the reaction, same amount of carbon dioxide is produced by compassion off meeting. So the total mass off carbon dioxide produced can be calculated as follows, substituting in the value for mama's off carbon excite number off moles off carbon or excite in tow. This formula here, the total mass of carbon dioxide produces 701.52 kilograms. Next considering the falling reaction meeting plus oxygen leads to carbon dioxide plus water. So according to the given reaction, the amount of water is twice the amount off meeting. Therefore, number off mold off water will be twice off. Meeting. That comes out to be 3 1880 molds substituting in the values off water into the given relation, we can find the total mass off what are produced. That is 574.32 kilograms. That's a lot of water, considering the falling reaction off compassion off meeting, as the number off mold off meeting require is already calculated in part A, which is 15,940 mole, we can calculate the number of moons off oxygen required, which turns out to be twice off molds off. Meeting that is 31,880 substituting in the value off mass off oxygen on number off molds off oxygen in tow. This relation, we can have the total mass off photo that is 102 0160 grams now as only 23% off areas oxygen. Therefore, the overall overall mass off oxygen is as follows, which is 443 5478 point to six grams substituting in the density off. Groping on Mars off propane we can finally, we can find the volume off Oxygen or Marshall Faulk season which stones out do we? 3635637.92 leader. This volume off here is required to provide oxygen for the combustion off meeting to eating our house. Oh, last. But if, as the electricity is 100% efficient in producing heat inside those, therefore the amount off heat required would be same as 3500. Killer ward the body As the efficiency off production on distribution off electricity produce in coal fire plant is approximately 40% their fire. We can use the unitary method to find 8750 kilowatt off energy is transferred, the moss off cooled required. It can be calculated as represented over here, which turns out to be £3872. This mask off cool isn't pounds, but the mass off cool required is in kilogram. So there's a correlation between pound and kilogram, which is represented by this using the common unitary method, we can convert pounds into kilogram. That turns out to be 1756.34 kilograms. This amount off cool is required to produce the electrical energy necessary to heat the house if the efficiency off production and distribution is about what he poisoned.