謝謝～

18~20為題組 在人類發展文明的過程中需要依賴能量,使用時必須依照需要將能量轉換成適當的形式。而在能量的形式 轉換的過程中,總有部分能量會逸散而損失,逸散的能量不易收回再加以利用,因此可供我們利用的「有 用能源」將愈來愈少,找尋新的能源是重要的課題之一。 據估計每年照射在地球表面上的太陽能約為目前全世界每年所需能量的一萬多倍,利用太陽能來發電 應是解決能源匱乏的良好方案。由近年歐盟統計資料(如下左圖)可一窺究竟。 目前人類利用太陽能通常有兩種方式: 一是太陽光照射在某些金屬表面上,使金屬的原子釋放電子,形成電流,轉為電能。最常見的就是太 陽能電池。 另一種方式是大規模的太陽能轉換成我們可使用的能源,然而最大的問題是:太陽並不是隨時都在照 射,以致無法全天候運轉。這問題的解決之道就是在太陽照耀的時候,除了發電裝置運作之外,還要將多 餘的照射能量儲存起來,以待天候不佳或夜晚的時候使用,但是在能量儲存與釋放的過程當中,損失的比 例很大,能量轉換的效率並不高,為各種發電型態中最低的。而近年來對於解決這個問題有了重大的突破 !因為有了熱量貯存媒介的新材料。在西班牙的安達索爾太陽能發電站(Andasol Solar Power Station), 利用直線型拋物面槽式集热器(如下右圖)將入射的陽光經由拋物面板反射,集中能量於拋物面的焦點( 實際上為一直線)處加熱金屬管內的油將水煮沸、產生蒸氣用來發電。實際上,拋物面集热器所收集的熱 能幾乎是白天發電所需熱能的兩倍,多餘的熱則會從管内的油傳送至熱量貯存媒介熔融鹽。其熔點為 240℃,在240℃至590℃的範園內都是很穩定的液態,比熱相當大,是很合適的熱貯存材料、熔融的混合 鹽從 260℃吸取油管的熱能升溫至 400℃。夜間則將熱傳回管內的油,以供發電。如此,發電廠在白天及 夜晚都能運作,既可提升效率又可降低成本,有如打造一個太陽能銀行般將太陽能貯存起來!

G小題錯在哪⋯

Au equation of state relates the state v (g) True false The internal energy of an animal cell (system) can only be changed by the flow of heat (9) or work (w) across the boundary between the system and surroundings. (4 points). s'open system m True false: Find the incorrect conclusions from the following sentences and correct them. (20 points).

51題，解答九分之一那邊，為何是cot3x的三次方而不是一次方，為何是九分之一不是三分之一？

Finding an Indefinite Integral In Exercises 49–58, find the indefinite integral. Use a computer algebra system to confirm your result. 49. cot 2x dx 50. tan Soor foset X X sec4 4 4 dx 51. csc4 3x dx 52. cores X X cot? csc4 – dx 2 2

第三題為何是3啊⋯⋯ expansion那內能差不就是小於0嗎，

(3) Pushing the piston down so as to do work on the system 3 PV a (c)Multiple Choice: What is the correct result for reversible isobaric process in which an ideal gas undergoes an expansion form 1 L to 10 L in a closed system? BU-atw DHECPAT (3 points) Pv=nRT AU=croTo (1)w > 0, AU>0,q>0; (2)w >0, AU<0,q<0; (3)w<0,AU>0,q>0; (4)w <0, AU<0,q<0 个小 finat low of thermodynamics takes the

第一題 怎麼想

1.) True/false, multiple choice or short answer. “*” denotes more than one correct answers. (33 points) (a) Multiple Choice: I will have the largest energy transfer as expansion work from an ideal gas system 1o the surroundings if I use a process that is (3 points) (1) Isothermal and quick ;(2) adiabatic and quick ;( 3) isothermal and slow; (4) adiabatic and slow

求救第55題 完全看不懂他要我幹嘛

Year slenue Req) = 1932 1958 +1000 q R 9)=-1000q =74 1963 1968 COM If the price in dollars of a stereo system is given by 1000 p(q) + 1000, 1000 ² q where q represents the demand for the product, find the mar- ginal revenue when the demand is 10. 54. Profit Suppose that for the situation in Exercise 53 the cost in dollars of producing a stereo systems is given by C(q) = 0.2q2 + 69 + 50. Find the marginal profit when the demand is 10. 59. Marginal Product of Labor The output y of a manufacturing y process is a function of the size of the labor force n using the function 1990 +1000 1971 1974 = 990 197 197 19 19 1 y = kVn. The marginal product of labor, defined as dy/dn, measures the rate that output increases with the size of the labor force, and is a measure of labor productivity. (a) Show that (c) Using the a cubic f respond the rate and 200 (d) Discus descri part ( the y (e) Exp data calc ful x C(x) = 58. Money 1955-7 dy k dn an (b) How can you tell from your answer to part (a) that as the size of the labor force increases, the marginal product of labor gets smaller? This is a phenomenon known as the law of diminishing returns, discussed more in the next chapter. 56. Profit An analyst has found that a company's costs and rev- enues in dollars for a product are given by x2 C and R(x) 2x 2 5000' respectively, where x is the number of items produced. (a) Find the marginal cost function. (b) Find the marginal revenue function. (c) Using the fact that profit is the difference between revenue and costs, find the marginal profit function. (d) What value of x makes the marginal profit equal O? (e) Find the profit when the marginal profit is 0. (As we shall see in the next chapter, this process is used to find marimum profit.) A wher in bi find year (a) (C) (e) nad since

21題 教教我QAQ

Section 11.3 Angular Momentum J-s behind rmv a he ur 265 = ? a ter 30. Example 11.1: A 58.1 Iw COMP string and whirled at 18. Express the units of angular momentum (a) using only the funda- momentum of magr mental units kilogram, meter, and second; (b) in a form involving the circular path. Fir newtons; (c) in a form involving joules. marw horizontal and (b) the 19. Use data from Appendix E to make an order-of-magnitude esti- 31. Example 11.2. A stai mate for the angular momentum of our Solar System about the Max 27 the end of its lifetime galactic center. mu = 17.293 of radius 4.96 X 10' 20. A gymnast of rotational inertia 63 kg•m? is tumbling head over heels dwarf of radius 4.21 with angular momentum 460 kg•m?/s. What's her angular speed? 17.99 acted on the core, fine A 660-g hoop 95 cm in diameter is rotating at 170 rpm about its 32. Example 11.2: Astro 22. A 1.3-th-diameter golf ball has mass 45 g and is spinning at central axis. What's its angular momentum? L: 1W=0-66*(0-95) x 140x277.10 km and determin core that collapsed to 3000 rpm. Treating the golf ball as a uniform solid sphere, what's ing with a period of 4 its angular momentum? 18-3 33. Example 11.2. The s 10-598 rpm With her arms outstre Section 11.4 Conservation of Angular Momentum tational inertia is 3.5 23. A potter's wheel with rotational inertia 6.20 kg•m? is spinning (Fig. 11.6b), her rot freely at 20.0 rpm. The potter drops a 2.50-kg lump of clay onto her final spin rate? L = 6 2 x 2-1 = 12-99~13 - 2x2 22 13= 60.48)" x 2.5 W W = 2 . X z W = 20x2T 60 ²2.1 ~ 1 12.574

第21題 到底要怎麼寫ಥ_ಥ

Section 11.3 Angular Momentum J-s behind rmv a he ur 265 = ? a ter 30. Example 11.1: A 58.1 Iw COMP string and whirled at 18. Express the units of angular momentum (a) using only the funda- momentum of magr mental units kilogram, meter, and second; (b) in a form involving the circular path. Fir newtons; (c) in a form involving joules. marw horizontal and (b) the 19. Use data from Appendix E to make an order-of-magnitude esti- 31. Example 11.2. A stai mate for the angular momentum of our Solar System about the Max 27 the end of its lifetime galactic center. mu = 17.293 of radius 4.96 X 10' 20. A gymnast of rotational inertia 63 kg•m? is tumbling head over heels dwarf of radius 4.21 with angular momentum 460 kg•m?/s. What's her angular speed? 17.99 acted on the core, fine A 660-g hoop 95 cm in diameter is rotating at 170 rpm about its 32. Example 11.2: Astro 22. A 1.3-th-diameter golf ball has mass 45 g and is spinning at central axis. What's its angular momentum? L: 1W=0-66*(0-95) x 140x277.10 km and determin core that collapsed to 3000 rpm. Treating the golf ball as a uniform solid sphere, what's ing with a period of 4 its angular momentum? 18-3 33. Example 11.2. The s 10-598 rpm With her arms outstre Section 11.4 Conservation of Angular Momentum tational inertia is 3.5 23. A potter's wheel with rotational inertia 6.20 kg•m? is spinning (Fig. 11.6b), her rot freely at 20.0 rpm. The potter drops a 2.50-kg lump of clay onto her final spin rate? L = 6 2 x 2-1 = 12-99~13 - 2x2 22 13= 60.48)" x 2.5 W W = 2 . X z W = 20x2T 60 ²2.1 ~ 1 12.574

求解 謝謝

The figure shows a three-particle system, with masses mu = 4.2 kg. m2 = 2.8 kg, and m2 = 7.3 kg. What are (a) the x coordinate and (b) the y coordinate of the system's center of mass? 13 2 1 x (m)

詢問成本與管理會計 第18題的題目是什麼意思 並且是怎麼算出來的

D. Materials, 40%; labor, 40%; overhead cost, 60%. E. Materials, 40%; labor, 40%; overhead cost, 100%. (18) Agora Company uses a process-cost system for its single product. Material A is added at the beginning of the process; in contrast, material B is added when the units are 75% complete. The firm's ending work-in-process inventory consists of 6,000 units that are 80% complete. Which of the following correctly expresses the equivalent units of production with respect to materials A and B in the ending work-in-process inventory? A. A, 4,800; B, 0. B. A, 4,800; B, 4,800. C. A, 6,000; B, 0. D. A, 6,000; B, 4,800. E. A, 6,000; B, 6,000. 19. Willingham uses a process-costing system for its single product, which is manufactured from Material X and Material Y. X and Y are introduced to the product as follows: Material X: Added at the beginning of manufacturing Material Y: Added at the 75% stage of completion