想問3-9的a跟c

Problems 3-1. Explain the difference between *(a) random and systematic error. (b) constant and proportional error. *(c) absolute and relative error. (d) mean and median. *3-2. Suggest two sources of systematic error and two sources of random error in measuring the length of a 3-m table with a 1-m metal rule. 3-3. Name three types of systematic errors. *3-4. Describe at least three systematic errors that might occur while weighing a solid on an analytical balance. *3-5. Describe at least three ways in which a systematic error might occur while using a pipet to transfer a known volume of liquid. 3-6. Describe how systematic method errors may be detected. *3-7. What kind of systematic errors are detected by varying the sample size? 3-8. A method of analysis yields masses of gold that are low by 0.4 mg. Calculate the percent relative error caused by this result if the mass of gold in the sample is (a) 500 mg. (b) 250 mg. V(c) 125 mg. (d) 60 mg. 3-9. The method described in Problem 3-8 is to be used for the analysis of ores that assay about 1.2% gold. What minimum sample mass should be taken if the relative érror resulting from a 0.4-mg loss is not to exceed *(a) -0.1%? (b) -0.4%? (c) -0.8%? (d) - 1.1%? 3-10. The color change of a chemical indicator requires an overtitration of 0.03 mL. Calculate the error if the total volume of titrant is percent relative (a) 50.00 mL. (c) 25.0 mL. 3-11. A loss of 0.4 mg of Zn occurs in the course of an percent relative analysis for that element. Calculate the error due to this loss if the mass of Zn in the sample is *(b) 10.0 mL. (d) 30.0 mL. 190 (c) 188 (d) 4.52 x 103 4.63 x 103 4.53 x 10 ³ √6 *(a) 30 mg. (b) 100 mg. *(c) 300 mg. (d) 500 mg. 3-12. Find the mean and median of each of the following sets of data. Determine the deviation from the mean for each data point within the sets, and find the mean devi- Vation for each set. Use a spreadsheet if it is convenient. *(a) 0.0110 0.0105 (b) 24.53 0.0104 24.68 24.81 24.77 39.61 862 (f) 850 MA 3-13. Challenge Problem: Richards and W the molar mass of lithium and colle data. 24.73 Experiment 1 2 3 4 5 6 194 447 X 10 7 448 X 107 4.58 X 10 (a) Find the mean molar t workers. (b) Find the median molar ma (c) Assuming that the cam molar mass of lithium is the absolute ertor and of the mean value demi Willard. (d) Find in the chemical ues for the molar mus since 1910, and ag a table or spreadshera 1817 given in the a Richards and Willd. Com mass versus year to la of lithium has chang Suggest possible abruptly about 18 ant de (e) The incredibly deals Richards and W that major changes will occur. Disc calculation in pat (f) What factors ha since 1910? (g) How would you mass? 6See Chapter 2 of Applications of Microsoft Excel in Analytical Chemistry, 4th ed., for information about statistical 7T. W. Richards and H. H. Willard, J. Am. Chem. Soc., 1910, 32, 4, DOI: 10.1021/ja01919a002. built-in statistical functions. "Answers are provided at the end of the book for questions and problems marked with an asterisk The I of ₂ or inc rce of able vas error c often in individu ate resul data in rtainties. dimensio andom e analysts The result

請問有人會這三題嗎

= 1x 10⁰ p -45. Perform the following unit conversions. meme a. Congratulations! You and your spouse are the proud parents of a new baby, born while you are studying in a country that uses the metric system. The nurse has gibre informed you that the baby weighs 3.91 kg and measures 51.4 cm. Convert your baby's weight to pounds and to ou ounces and her length to inches (rounded to the nearest 3.91 quarter inch). 4536 =8 9.9102 10 20. 2 in, 2b. The circumference of the earth is 25,000 mi at the equa- tor. What is the circumference in kilometers? in meters? 三 c.) A rectangular solid measures 1.0 m by 5.6 cm by 2.1 dm. Express its volume in cubic meters, liters, cubic inches, and cubic feet.

生物～植物部分 想請問A.B是錯在哪～感恩！

> > 我。 84.下列有關維管束植物根部發育與構造的敘述,何者錯誤? A. 維管束植物成熟時,均具有直接由胚根(radile)發育而形成的根系構造 B. 軸根系的雙子葉植物與鬚根系的單子葉植物,其根部都會形成支 C. 位於植物的莖部與莱部形成的不定根,有可能再形成支根 D. 支根大都形成於較成熟之根毛區, 藉此與主根的維管束得以連結 E. 當維管束植物氮源缺乏時,根部即與真菌共生形成菌根,或與細菌共生 成根瘤 > Kte

為什麼不是E

Q搜尋 07.pdf Chapter 7: Atomic Structure and Periodicity 1. When ignited, a uranium compound burns with a green flame. The wavelength of the light given off by this flame is greater than that of A) red light B) infrared light C) radio waves D) ultraviolet light E) gamma rays ANS: D PTS: 1 DIF: Easy REF: 7.1 KEY: Chemistry | general chemistry | atomic theory light | electromagnetic radiation MSC: Conceptual 2. Which form of electromagnetic radiation has the longest wavelengths? A) gamma rays

普物-請問第41題

41。The surface of the continental United States has an area of about 8x 106 km2 and an average elevation of about 500 m (above sealevel. The average yearly rainfallis 75S cm.The frac- tion ofthis rainwaterthatreturns tothe atmosphere by evapora- tion is生the rest eventually flows into the ocean. Ifthe deerease in gravitational potential energy of the water-Earth_ system associated with that flow could be fully converted to eleetrieal energy, what would be the average power? (The massoflm'of water is 1000 kg.) 人 loon reaches its maximum height? potential energy is taken to be Zere its value atthe launch point) (D W 48 Avoleanicash ttowismovint eneountersa8.0” upslope.The ff up the slope before stopbing. As the flow Ift the flow and thus ground negligible: assume als the front ot the flow is conserve

求全部詳解，在線等，急QQ(可以部分就好QQ

Pt 謹., 【G@放|中葉生說1 2018-test2-ch26-30 - 訪取0專用 入 圖 器 當數: so=8.85x1072F/m 一、選擇題:每題5分。 1一平行板電容器,若其每板面積為 100 cm?、兩板相距2mm。用 80V 的電池充滿電後,電容上的電荷量為: 0885nc; (8) 177nc;(c)354nc;(0) 708nc (51416nc。 2 南顆電容 G =10uF、G0=20 jiF 串聯後再連接一烽 12 V 的電池。求兩顆踢容總共儲存的能星。 多360p; 480nJ (0) 600nJ; (0) 720 1; (E) 840nJ。 3 一2hF 的平行板電容器,將其連接至 200V 的電池,充滿電後, 不移開。再將介電常數 <=10 的電 介質填滿十板間的空間,則此時電容儲存的艇量為多少?(多005J;(8) 01J;(c) 02J;(D) 04J; 四08 J 4 如右回,電容 帶電 0-8hC,電容 3C不帶電。將開辣閱上,經很久達平衡(此時電流為零)。若C=1hF,則從開始到最終 平衡時,電月R總共消耗的能星為 (8mJ; (8) 12mJ3 (0 16m (0) 20m0; 24nJ。 5 一 吃放電線路 :A=104Q,C=200 hF,電容的初電荷為10 mc。/=0 時,開始放電,則/=2s時,電流為 (人 184mAy 個368mA;(c) 539mA;(D)717mA; (E 904mA2 6一電荷 ?,其骨時速度# = 玉m/s,位於均勻磁場中2-(F+ 縣 245T,則其受力了= (CC2二片絡 (2C244片3 (02C2二中遇 (0)22中片朮(5202中4此嫩 7 一電子(=91x103 kg 7= 1.6x10? 0)以 1.2X10? m/s 的遠率進入一均勻磁場區域內作圓周運動磁場方向與速度方向垂 直, 若磁場大小為 01T,則其財期為 (A 12x1009s7 (8)36x100s; (tc)62x1006s;(0)76x1030s (四97x1009s。 8右圖中立方體的邊長為 40 cm, 電流 /= 10 A, 均勻磁場 52=02T, 則 09 段受到的磁力為: 人(95(症生N (80s(二全N3 (095二生N) (Do9sFN3(ED-95N3 二、計算題 1. Foureapactors are connectedas shownimnFig 1 Take Go 4pnF,人6 @2nF, =2nFande=14V Fmnd (the equivalentcapacitance;(b) the charge on Gi (c) the potentaldifferenceacross @(12仿 2 Forthe Acchargng crcutofFig 24akeA=100kg,c= 2nF,ande=20V heswitchisclosedat/=0.Fnd (a) tme constant tb) he maximum charge and curent (c) the charge on ihe capacftorat/=015(d) hecurentat/015(@ thepowerimthebatteryat/=01s。(20幼 3 Find (a) the currents 4、&and 6; (b) the potental difference between ponts 2and cinFig 3.(15 約 4 圖四的電路,將開關關上,經很久以後,(a)電流 +、/Z各為何 ? (b)電容上的電荷量為何 ? (c) 今將開關打開 ,則經多久後電容 的電荷量為10uC。(12 爺 5 如圖五,兩根通電流的長直導線:4=3Aand&=5A。若 7= 20 cm,求 人點磁場及與吃。(10 分)

求解圖裡UICK quiz的第二小題

acit0r 1taneOuls CUrTent Differentiating Equation 27.22 with respectto time gives the inst: as afunction of time: 4 tt號 一Fe ptasafurc 主二 where Q;/有CC 三方 is the initial current. Figure 27.15b 5 in the resistor that we guessedin order to-apply Kirch Equations 27.15 and 27.21. Equation 27.23 shows that the ci ing capacitor is negative, indicating that the current 1s Figure 27.15c. Both the charge on the capacitor and the ct tially at a rate characterized by the time'constant7了三用C. 人 i 一 GOuicK ouiz 27.5 Considerthe circuitin Figure 27.17 and assume the battery has after the switch is closed, what is the currentin the Figure 27.17 no internal resistance. () 」 battery (a) 0 (b) &/2A(G 28/Z04 8/元(e) impossible to determine (ii) After a 有 eyerylong time, what is the Currentin the battery? Choose from the same choices. theswitch is CC (3 前:銜1加信介2放 IntermittentWindshield Wipers nobiles are equipped with windshield wipers that can operate intermittently during alight rainfall. How does ofsuch wipers depend on the charging and discharging ofacapacitor7 民 The wipers are part ofan 及C circuit whose time constant can be varied by selecting different values of及through amultipo- Sition sWitch. As the voltage across the capacitor increases, the capacitor reaches a point at which it discharges and Higgers the wipers. The circuit then begins another charging cycle. The time interval between the individual sweeps of the wiperS 1 determinedjby the value ofthe time constant.

再來個笨問題 沒有初速要怎麼辦

1 攻Mby Iceketreachesaheight of 72.3 m and lan Whatwas the angle oflaunch? ds 111 m from the Jaunch Poinf wifh no ar