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1、The problems of the first law1.1 a lead bullet is fired at a frigid surface. At what speed must it travel to melt on impact, if its initial temperature is 25 and heating of the rigid surface of the rigid surface is neglected? The melting point of lead is 327. The molar heat of fusion of the lead is
2、4.8kJ/mol. The molar heat capacity CP of lead may be taken as 29.3J/(mol K)铅子弹射向一个寒冷的表面。在什么速度必须前往融化的影响,如果它的初始温度是25,加热的刚性表面刚性表面被忽视?铅的熔点为327。的摩尔熔化热铅是4.8焦每摩尔。摩尔热容CP的铅可能作为29.3 j /(摩尔K)Solution: 1.2 what is the average power production in watts of a person who burns 2500 kcal of food in a day? Estimate t
3、he average additional powder production of 75Kg man who is climbing a mountain at the rate of 20 m/min什么是平均功率的生产在一个人谁燃烧2500千卡的食品在一天的瓦特？估计平均加粉生产75公斤人谁是登高山以20米/分的速度Solution 1.3 One cubic decimeter (1 dm3) of water is broken into droplets having a diameter of one micrometer (1 um) at 20.(a) what is the
4、 total area of the droplets?(b) Calculate the minimum work required to produce the droplets. Assume that the droplets are rest (have zero velocity)Water have a surface tension of 72.75 dyn/cm at 20 (NOTES: the term surface energy (ene/cm2) is also used for surface tension dyn/cm)水一立方分米（1立方分米）被分成20，直
5、径一微米（1微米）的液滴。（一）什么是液滴的总面积？（b）计算需要产生的液滴的最小工作。假定液滴垫（具有零速度）水具有72.75达因/厘米的表面张力在20（注：术语表面能量（烯/厘米2）也可用于表面张力达因/厘米）Solution 1.4 Gaseous helium is to be used to quench a hot piece of metal. The helium is in storage in an insulated tank with a volume of 50 L and a temperature of 25, the pressure is 10 atm. As
6、sume that helium is an ideal gas.(a) when the valve is opened and the gas escapes into the quench chamber (pressure=1 atm), what will be the temperature of the first gas to hit the specimen?(b) As the helium flows, the pressure in the tank drops. What will be the temperature of the helium entering t
7、he quench chamber when the pressure in the tank has fallen to 1 atm?气态氦被用于骤冷一热的金属片。氦是在存储在隔热的罐体积为50升和25的温度下，压力为10个大气压。假设氦是一种理想的气体。（a）该阀打开，气体逃逸到激冷室中（压力=1atm）中，这将是第一气体的打试样的温度时？（b）由于在氦气流，在罐中的压力下降。会是怎样进入骤冷室中的氦气的温度时，在罐中的压力降低到1个大气压？Solution: 1.5 An evacuated (P=0), insulted tank is surrounded by a very lar
8、ge volume (assume infinite volume) of an ideal gas at a temperature T0. The valve on the tank is oened and the surrounding gas is allowed to flow suickly into t(e tank until the pressure insie the tank is equals the pressure outside. Assume that no heat flow takes place. What is the0final tempeture
9、kf te gaS in the tank? The heat cap!city mf the gas, Cp and Cv each ay be(assumed to be c/nsuantp and SvMhint: one way to approach the xroblem is to define the system as the gas ends up in the tank.抽成真空（P= 0），辱骂箱由在温度T0的一个非常大的量的理想气体的（假定无限量）包围。水箱上的阀是oened和周围的气体被允许流动suickly成吨（例如罐，直到压力insie罐是等于外界压力。假定没有
10、热流发生。这是the0final tempeture kf的TEE气？！在罐中的热帽城市MF的气体，Cp和CV每个IAY被（假定为c/ nsuantp和SvMhint：接近xroblem的一种方法是定义系统作为气体结束了在罐中。solution 1.6 Calculate the heat of reaction of methane with oxygen at 298K, assuming that the products of reaction are CO2 and CH4 (gas)This heat of reaction is also called the low calor
11、ific power of methane convert the answer into unites of Btu/1000 SCF of methane. SCF means standard cubic feet, taken at 298 and 1atm计算的甲烷与氧气的反应热在298K，假定反应的产物是二氧化碳和甲烷（天然气）反应的该热也被称为甲烷的低发热量转换的答案为英制热量单位/ 1000的SCF联信甲烷。 SCF是指标准立方英尺，在298和1大气压采取NOTE: this value is a good approximation for the low calorific
12、 powder of natural gasDATA: solution1.7 Methane is delivered at 298 K to a glass factory, which operates a melting furnace at 1600 K. The fuel is mixed with a quantity of air, also at 298 K, which is 10% in excess of the amount theoretically needed for complete combustion (air is approximately 21% O
13、2 and 79% N2)(a) Assuming complete combustion, what is the composition of the flue gas (the gas following combustion)?(b) What is the temperature of the gas, assuming no heat loss?(c) The furnace processes 2000kg of glass hourly, and its heat losses to the surroundings average 400000 kJ/h. calculate
14、 the fuel consumption at STP (in m3/h) assuming that for gas H1600-H298=1200KJ/KG(d) A heat exchanger is installed to transfer some of the sensible heat of the flue gas to the combustion air. Calculate the decrease in fuel consumption if the combustion air is heated to 800K甲烷输送在298K到玻璃工厂，而经营一个熔化炉，在1
15、600 K的燃料与空气的量在298 K，这是10的过量理论上所需要的完整的燃烧量（混合时，也空气是约21的O 2和79N 2）（一）假设完全燃烧，什么是烟道气（燃气燃烧以下）的组成？（二）什么是气体的温度，假设没有热损失？（三）炉处理的玻璃2000公斤每小时，并且它的热损失到周围环境中的平均400000千焦耳/小时。在计算STP的燃油消耗（以m3/ h）的假设气体H1600-H298=1200KJ/ KG（d）一个热交换器安装将一些烟道气的显热的燃烧空气。计算燃料消耗的降低，如果燃烧空气被加热到800KDATA STP means T=298K, P=1atm Solution1.8 In a
16、n investigation of the thermodynamic properties of a-manganese, the following heat contents were determined:H700-H298=12113 J/(g atom) H1000-H298=22803 J/(g atom)Find a suitable equation for HT-H298 and also for CP as a function of temperature in the form (a+bT) Assume that no structure transformation takes place in the given tempeture rang.Solution 1.9 A fuel gas
