Download ENSC 2213 Thermodynamics Exam 1, Spring 2012 - Prof. Arland Johannes and more Exams Thermodynamics in PDF only on Docsity! DISCUSSION SECTION # NAME ENSC 2213 THERMODYNAMICS Spring 2012 – EXAM 1 Instructions for taking examinations 1. Do not open the exam until you are told to do so. When told to start, put your name on each page and your discussion section number in the space provided above. 2. This test is open book, open syllabus and one page of notes. 3. Do not exchange anything with your neighbors during the exam. 4. Show all work. Use diagrams and show control volumes as needed! Identify reference points clearly and unambiguously. Write equations in variable form before entering numbers. Answers that are unsupported will not be accepted. Cross out (clearly) or erase all work that you do not want to be graded. 5. All answers should be given to a reasonable degree of precision - usually to three significant figures. Excessive or insufficient precision will be penalized. 6. Every answer must include correct units. 7. Identify your final answer by boxing it in. 8. The examination will be stopped promptly at the appropriate time. Stop writing when told to do so and pass the exam papers towards the aisle immediately. 9. Unless you finish prior to 10 minutes before the exam finish time, please remain in your seat until all exam papers have been picked up. 10. The number in parentheses in each problem indicates the number of points for that problem. Note that problems may not be of equal weight. ENSC 2213 Thermodynamics NAME EXAM 1 / 2-3-12 2 (25) Problem 1. A container contains 1.2 moles of liquid water (MW=18.0 g/mol, = 999 kg/m3) and has a temperature of 42F. Calculate the following: a) The temperature in R b) The temperature in K c) The mass of the water in grams d) The mass of the water in lbm e) The weight of the water lbf f) The weight of the water in newtons g) The number of lbmoles. h) The specific weight in lbf/ft 3 i) The molecular weight in lbm/lbmole ENSC 2213 Thermodynamics NAME EXAM 1 / 2-3-12 5 (25) Problem 4. Superheated steam is contained in a high pressure piston-cylinder assembly at initial conditions of V1=1 ft 3, p1=100 psia, u1= 1214.2 Btu/lbm, and v1=6.216 ft 3/lbm. The steam is expanded in a non-linear process where pV=constant to state 2 where V2=3V1 and u2=1217.2 Btu/lbm. (a) What is the weight of the steam in the cylinder in lbf ? (b) How much work (in Btu) is done during this process? Is it done on or by the steam? (c) How much heat (in Btu) is transferred during the process? Is it transferred to or from the steam? ENSC 2213 Thermodynamics NAME EXAM 1 / 2-3-12 6 Problem 1 /25 __________________ Problem 2 /25 __________________ Problem 3 /25 __________________ Problem 4 /25__________________ Total Score /100_________________
