Ultimate Engineering Study Guide - Questions & Answers

Considering that air is being compressed in a polytropic process having an initial pressure and temperature of 200 kPa and 355 K respectively to 400 kPa and 700 K.a) Calculate the specific volume for both initially and final state. (5)b) Determine the exponent (n) of the polytropic process. (5)c) Calculate the specific work of the process. (5)
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Do not use the lumped model for this transient problem.A metallic cylinder with initial temperature 350C was placed into a large bath with temperature 50C (convection coefficient estimated as 400 W/m2 K). A diameter and a height of the cylinder are equal to 100 mm. The thermal properties are:conductivity 40 W/mK,specific heat 460 J/kgK,density 7800 kg/m3Calculate maximum and minimum temperatures in the cylinder after 4 minutes.This is a short cylinder.
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An electrically heated stirred tank system of section 2.4.3 (page 23) of the Textbook is modeled by the following second order differential equation: 9 d 2T/dt 2 + 12 dT/dt + T = T i + 0.05 Q where T i and T are inlet and outlet temperatures of the liquid streams and Q is the heat input rate. At steady state T i,ss = 100 oC, T ss = 350 oC, Q ss=5000 kcal/min (a) Obtain the transfer function T(s)/Q(s) for this process [Transfer_function] (b) Time constant and damping coefficient in the transfer function are: [Tau], [Zeta] (c) At t= 0, if Q is suddenly changed from 5000 kcal/min to 6000 kcal/min, calculate the exit temperature T after 2 minutes. [T-2minutes] (d) Calculate the exit temperature T after 8 minutes. [T-8minutes]
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A cylindrical having a frictionless piston contains 3.45 moles of nitrogen (N2) at 300 C having an initial volume of 4 liters (L). Determine the work done by the nitrogen gas if it undergoes a reversible isothermal expansion process until the volume doubles.
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Feedback control system to control the composition of the output stream in a stirred tank blending process is shown in Figure 11.1, page 176 of Textbook (as shown below). fig 11 Mass fraction x of the output stream is the controlled variable, flow rate w 2 of the input stream is the manipulated variable and mass fraction x 1 of the other input stream is the disturbance variable. The following data are available: Volume and density are constant. V= 3.2 m 3, rho= 900 kg/m 3 The process is operating at steady state with w 1=500 kg/min, w 2= 300 kg/min, x 1= 0.4, x 2= 0.8 G m= K m = 16 mA/(mass fraction), G v= K v = 20 kg/min mA The process transfer function G p= X(s)/W 2(s) = K 1 /(s+1) where = Vrho/w and K 1 =(1-x)/w The transfer function relative to the disturbance variable G d = X(s)/X 1(s) = K 2 /(s+1) where K 2 = w 1/w A PI controller is used with K c=3 and I = 1 min The set point for the exit mass fraction x is set at the initial steady state value. (a) If the disturbance variable x 1 is suddenly decreased to 0.2 from the initial steady state value of 0.4, derive an expression for the response of outlet composition x to this step change . (b) Calculate the composition of the exit stream (x) 1 minutes after the change. (c) Calculate the composition of the exit stream (x) 2 minutes after the change. (d) What is the composition x when a new steady state is reached? (e) What is the offset?
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Chuse the correct ERGY s temperature B. M Molecules the 1 and bland 19. What is at 25C for the followers COCO.(a) a. 21 b. 45.9 217 B_20. Choose the incorrea statement Gases have less entropy than their solids Solutions have more entropy than the solids dissolved. c. Gases have more entropy than the liquids d. Liquids have more entropy than there solids. Entropy of a substance increases as its temperature increases. 21. Which of the following statements is true? Spontaneous processes proceed without outside intervention b. A spontaneous reaction is a fast reaction. c. Only exothermic processes are spontaneous. d. All the statements are true. B 22. Which of the following processes is non-spontaneous? a. Salt dissolves in water b. Photosynthesis occurs C. Ice cream melts on a hot summer day d. Hot soup gets cold before it's served 23. The change in free energy for a reaction: a. predicts speed c. equals heat b. equals AH-TAS d. depends on the standard state chosen 24. In a sealed container, the rate of dissolving is equal to the rate of crystallization would expect: d. N a. AS=0 b. AGO C. AG = 0 25. A reaction is spontaneous if 1) AG is a negative value. 11) Both enthalpy and entropy increase. III) AH is negative and AS is positive. IV) Both enthalpy and entropy decrease. V) AH is positive AS is negative. a. III and IV b. I and 111 c.land 11
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A gas initially at a pressure of 40 kPa and a volume of 100 mL is compressed until the final pressure of 200 kPa and its volume is being reduced to half. During the process, the internal energy of the gas has increases by 2.1 KJ. Determine the heat transfer in the process.
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Drying a siab of material at 6500 + lam with air at 24. humidity at a velocity of 1.5 m/s, Estimate the drying rate in the constant rate regime by determing the mass transfer coefficient (ky) for flow across a fiat plare. Tengen of : 2-0.5m Ai viscos 174 : M = 20,21-10-4epais Alv density: P-1.045 kg/m3 Diffusivery of waterinar: DAB = 0,288 (mysar M Wair=28,97 YBM = 1 420
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Calculation of AU Using American Engineering Units Saturated liquid water is cooled from 80F to 40F still saturated. What are A, AU, A, AP, and A?
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Draw the P&ID of a process used to increase the sugar concentration of a maple syrup in an evaporator. The maple syrup is heated by passing through a steam heat exchanger. Two control systems are installed on this process A level control system to maintain a constant level of syrup inside the evaporator An analytical control system to monitor the sugar concentration of the syrup. This analytical system will control this concentration by adjusting the steam flow reaching the heat exchanger .
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Which of the following is NOT part of a car's drive train?A axleB rotorC differentialD transmission
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For laminar flow of air over a flat plate that has a uniform surface temperature, the curve that most closely describes the variation of the local heat transfer coefficient with position along the plate is
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The statement that is correct about the relation between the velocity boundary layer and heat transfer for flow over a flat plate that is uniform in temperature is
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Water enters and leaves a pump in pipelines of the same diameter and approximately the same elevation. If the pressure on the inlet side of the pump is 30 kPa and a pressure of 500 kPa is desired for the water leaving the pump, what is the head that must be added by the pump
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. (5 points) Based on the Reynolds number for each of the following objects, identify each flow as either inertial or viscous force dominant and in which cases the flows are laminar or turbulent. Flow Re A. A bee larva in honey 0.2 B. A ball tossed on Mars 500 C. An elderly driver on i95 1,2000,000
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How to Cancel prescription
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For a pipe system with a pump (pumping uphill), the change in elevation is 400 feet and the total head loss is 408.5 feet. Assuming gage pressure at the entrance and exit and no difference in velocity between the entrance and exit, determine the total energy transferred to the water. Estimate the required power input if the pump efficie
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: Mt nn kinh t c cu trc nh sau:C = 80 + 0,8(Y - T); T = 100 ;I = 130; G = 120; MSr = MS/CPI = 200; MD = 0,2Y 10iYu cu: 1. Xc nh thu nhp v li sut cn bng? 2. Mun sn lng cn bng tng 500 th chnh ph cn thay i thu nh th no? 3. Liu mc tiu cu 2 c th t c bng chnh sch tin t hay khng? Ti sao?
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A cylindrical space capsule lands in the ocean. This capsule is 2.44 m long, 1.10 m in diameter, and weighted at one end so that it floats with its long central axis vertical and 0.820 m of its length above the water surface. The mass density of sea water is 1025 kg/m3.What is the magnitude of the buoyant force exerted on the capsule?
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to check for ripple voltage from the alternator, connect a digital multimeter and select
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Things to be done before isolation
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What is planning in pretech
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Hi, can anyone draw me an isometric image of this shape?
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A particle which moves in two-dimensional curvilinear motion has coordinates in millimeters which vary with time t in seconds according to X=2t^2 +3t1 and y = 5t - 2. Determine the coordinates of the center of curvature C at time t = 1s.
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