Mechanical Engineering Questions and Answers June 18, 2021

A field is expressed in spherical coordinates by E a (25R). a) Find E and Ex at the point P(3, 4, 5). b) Find the angle that E makes with the vector B a.2 a,2 a, at point P.

Consider the inverted slidercrank mechanism shown, where a spring is connected between the tip of link (3), point B, and point R on the ground. The data for this system are given as C L OA0.20, L QB 0.8 m a b 0.4, c 0.5 m m 0.1, m 0.2, m 0.3 kg J 0.01, J 0.05, J 0.02 kg.m k 1,000 Nm, L 0.3 m Gravity acts in the negative y direction. A

obtain C. a. Natural frequency wn and damping ratio b. Damped frequency wa if applicable, and second order system time constant Using Laplace transforms, obtain the characteristic polynomial of the system, and find its roots. For each case, state, based on the roots (or, based on value) whether the system is underdamped, critically damped, or

4. 1) PWAB 2) PWAC 3) Thus 4) A A AB AC 1) PWAB 2) PWAC 4) pw 4 3) Thus (AB)pw AC M M is retained. M M is retained.,A government agency is planning a new office building close to its current headquarters. Four proposed sites are to be evaluated. Any of these sites will save the agency 700,000 per year, since two of its current satellite

F311. The material for the 50mmlong specimen has the stressstrain diagram shown. If P 150 kN is applied and then released, determine the permanent elongation of the specimen. (MPa) 500 450 0.00225 P 0.03 F31011 20 mm P (mmmm)

Air enters the compressor of a cold airstandard Brayton cycle with regeneration at 100 kPa, 300 K with a mass flow rate of 6 kgs. The compressor pressure ratio is 10 and the turbine inlet temperature is 1400 K. The turbine and compressor each have isentropic efficiencies of 80 and the regenerator effectiveness is 80. For k1.4 calculate the 4.1

QUESTION 2 Air enters the compressor of an ideal Brayton refrigeration cycle at 140 kPa, 270 K, with a volumetric flow rate of 1 ms and is compressed to 420 kPa. The temperature at the turbine inlet is 320 K. Determine. 2.1 The net power input, in kW 2.2 The refrigerating capacity, in kW. 2.3 The coefficient of performance. 2.4 The coefficient of

Read over this true story and decide if such an approach can be feasible in every industry. Provide substantiation for your answer by seeking out articles on line that discuss other firms attempts at team projects. Robert F. Hettinger, a venture manager with Signode Industries, Inc., in Glenview, Illinois, smiles as he recounts the strategy

Construct IPR of a well in a saturated oil reservoir using both Vogels equation and Fetkovichs equation. The following data are given Reservoir pressure, p 3,500 psia Tested flowing bottomhole pressure, Pwf1 2,500 psia Tested production rate at pwf1.91 600 stbday Tested flowing bottomhole pressure, Pwf2 1,500 psia Tested production rate at

Romeo tries to reach Juliet by climbing with constant velocity up a rope which is knotted at point A. Any of the three segments of the rope can sustain a maximum force of 2kN before it beaks. Determine if Romeo, who has a mass of 65kg, can climb the rope with constant velocity.,B 60 A C

5 The simply supported beam shown in Figure 4 is 10 metres long. It carries a vertical load of 20 kN at 3 metres from the lefthand end, a vertical load of 25 kN at 2 metres from the righthand end and a UDL of 10 kNm extending 8 metres from the lefthand end. The crosssection of the beam is shown in Figure 5. Youngs Modulus of Elasticity 190 GNm

At the beginning of the compression process of an Otto Cycle, the pressure, Volume and Temperature are found to be 102kNm2, 0.0025m3 and 190C respectively. If the maximum pressure in the cycle is not to exceed 4.6MNm2 and the volume ration of the cycle is 91, determine the following if the cycle is repeated 3000 timesmin (i) Parameters of state

A wellinsulated piston cylinder contains air initially of 0.01 m at 1.5 bar, 30C. The cylinder is connected to an air supply pipe via a valve. Air in the supply pipe is at constant 4 bar pressure and 30 C temperature. Now the valve is opened, air is pumped into the cylinder until the air volume inside the cylinder becomes 0.02 m. In this process,

250 mm 300 mm A B C 30mm diameter 50mm diameter PROBLEM 2.51 A rod consisting of two cylindrical portions AB and BC is restrained at both ends. Portion AB is made of steel (Es200 GPa, as 11.7 x 10C) and portion BC is made of brass (E 105 GPa, ab 20.9 x 10C). Knowing that the rod is initially unstressed, determine the compressive force induced in

1. A thermocouple junction, which may be approximated as sphere, is to be used for temperature measurement in a gas stream. The convection coefficient between the junction surface and the gas is h 400 Wm.K and the junction thermophysical properties are k 20 Wm K, c 400 JkgK and p 8500 kgm. Determine the junction diameter needed for the

Q.1 The air is compressed adiabatically in a combined pistoncylinder from 1 bar, 300 K to 10 bar, 600 K. Determine the work done, in kJ per kg of air, and the amount of entropy produced, in kJK per kg of air. The air is modeled as an ideal gas and the effects of the kinetic and potential energy are insignificant. What is the theoretical minimum

The Big Beef Restaurant has the following standard for a roat beef dinner Cooked beef Roasted potatoes Steamed vegetables Dinner roll 7 oz 8 oz 2 oz 1 roll The following is the purchase specifications Roast beef Potatoes Vegetables Dinner rolls Loss in Unit Price Trim Cooking Purchase Unit Purchase 15.00 0.055 6.50 0.30 15 lb 100 lb 0.45 lb 50

Assume a Legal Entitys capital structure consists of the following accounts: Short-term note payable $ 200,000 Long-term note payable 500,000 Mandatorily redeemable preferred stock 350,000 Common stock 60,000 Additional paid-in capital 400,000 Retained earnings 280,000 Total liabilities and equity $1,790,000 What is the maximum amount of

A 1500 cc IC engine working on a 4-stroke Otto cycle has a compression ratio of 11. Estimate the efficiency, peak pressure, and peak temperature if the output is 40 kW when running at 3000 rpm. If the engine is to run on a Diesel cycle, estimate the compression ratio, cut off ratio, efficiency, and output at 3000 rpm when peak pressure and peak

The three-element springs and dashpot model shown is subject to a creep experiment. Show how the length (or strain) increases with time. At time t the stress is removed. Show how the sample recovers.

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Design a system that utilizes renewable energy sources to power a remote mechanical engineering research facility located in a harsh, off-grid environment. Consider factors such as energy efficiency, reliability, and the environmental impact of the chosen renewable energy technologies.

In a manufacturing plant, the production line for a certain component is experiencing vibrations that are affecting product quality. You are tasked with identifying and mitigating the vibration issue. Outline the steps you would take to diagnose and resolve this problem.

1. a) Explain the manufacturing aspects of design. b) List the different design considerations. c) How ductility can be estimated from tensile test data d) Explain creep curve. e) Explain factor of safety used in design. 05x02 10 2. A socket and spigot cotter joint transmits an axial load of 60 KN. Design the spigot and cotter (Cotter must be

Calculate the performance ratio, specific heat transfer area, specific flow rate of cooling water, conversion ratio, and salinity of brine blowdown for a single stage flash desalination unit operating at the following conditions Feed salinity 45000 ppm Feed temperature 25 C Heating steam temperature 90 C Production capacity 1 kgs Brine

If water rises 7 m inside a piezometer inserted at point A, calculate whether there is quick sand condition at point A.,11 m Excavation. Dry soil p2000 kgm Acquifer 5m

For the limiter circuit shown below consider that the Zener diode has V4V and r. 5002. Also assume that the zener diode will have a constant voltage drop of 0.7V when forward biased. O Obtain its transfer characteristic equations and then, sketch and label the voltage transfer characteristic for input voltages between 15V. 2 1kn 1kn Z

The given p v diagram (not to scale) shows a closed system undergoing a power cycle using water. The cycle comprises of four sequential processes. The Process 12 and Process 34 are isobaric, while Process 2 3 and Process 41 are isochoric. Note that State 1 and State 3 are in saturated vapor phase. The maximum pressure in the cycle is 20 bar,

Find the flame temperature of the products of combustion of hydrogen and oxygen whose composition and average specific heats are given in the table below. The reactants enter the adiabatic combustion chamber at 250 K. In this table, Cpp is the average molar specific heat of the component between 298 K and the flame temperature, Cp is the average

What is the percentage of solids by weight for SherwinWilliams B67R5 O a. 4 O b. 65 O c. 2 O d. 81 2,What is the percentage of solids by volume for SherwinWilliams B67R5 O a. 2 O b. 4 O c. 81 Od. 65

The solution to the Dirac equation (eigenspinor ) for positive energy is with N =E+m. It can be seen that an eigenvalue has two eigenspinors, which means there is a decline in the eigenvalue (energy). This shows that there are other quantities that are commuting with Hamilton but has different eigenvalues between u(1) and u(2). You might think

u(1) N 1 0 P Em PriPy Em 0 1 NPiPy u(2) N Etm P Em

Figure (4) shows a PID control system, where Gr(s) is 1 G(s) (s1) The PID controller (parallel form) is assumed to be of the form K(sa) Gc(s) S i. Using polezero cancellation (setting a 1), find suitable values for K, such that the closedloop system will have a dominant first order pole at 2. For the design of part (i), find the values of ii. .

Suppose an 82 kg person in a wheelchair is moving over rough ground. At the speed they are traveling, the frequency of vibration is 60 rads and the persons displacement is 2.3 times as large as the grounds displacement. If the person moves a little faster, their displacement decreases. Assume the wheelchairs suspension system has negligible but

Consider a steam turbine, similar to the one at UConn Co-Gen Power Plant. The mass flow rate of steam is 1.5 kg/s and the heat loss from the turbine is 8.5 kW. Find the steady state power output of the turbine under the following operating conditions: Inlet Exit Pressure (bar) 20 1 Temperature ( o C) 360 Not Given Quality (%) Not Given 100

The members of the truss shown are to be made from solid circular rods. What rod. diameter is needed for the normal stress to be 100 MPa in (a) member EG, (b) member FG 15 kN 15 kN 15 kN A E 4m B D F H 5 KN 5 KN 5 KN 3m 3m 3m

Consider the real number r a b2 where a and b are rational numbers. Prove that there cannot exist a different pair of rational numbers (c, d) such that r c dv2

In the following circuit apply Voltage Divider Rule (VDR) and find, a) The Average Power and the Reactive power in the load b) The power factor in the load. Indicate if is leading or lagging Ri 252 j252 60 Vrms ZL Vs R 252 www Note the source is RMS value R 252 Zc Load j292

What is the effect of noise power in the bandwidth of a digital system? Draw illustrations to prove your answer.

a Use the properties of delta function to find the Fourier transform of ix(t) A cos(ct) ii y(t) A sin(act) Then plot their magnitude and phase spectra assuming A2 V and fe10 kHz. b Prove the results depicted in Fig. 4. 87(1) T O (a) T 2T 0 030 2at (6) Fig. 4 Unit impulse train and its magnitude spectrum. (22)

Consider the system: Where the shaft connecting the motor to the load is considered rigid and the inertia of the pinion is negligible. A) Write a state representation of the system taking as input the voltage v(t) applied to the motor and as output the position X(t) of the block M1. B) Considering the following internal parameters of the motor Km=

V IA MOTOR DC G M1 R X Zv B1 XXXXXXXXXXXXXXXXXX

solve to these three equations to find the unknowns of NB NA FA F and FB.

F 0 F, 0 ( 0 F 30 0.3m Solving Eqs. (1) to (5), 2000(981) N 0.75m NA FAMS NA 0.3 NA FB My NB 0.3 NB Im NB 8114.93 N NA FAFB F cos 30 0 Fsin 30 NA NB 2000(9.81) 0 F cos 30(0.3) F sin 30(0.75) Friction. It is required that both the front and rear wheels are on the verge to slip. Thus F 5793.16 N 5.79 KN 1.5m NB (2.5) 200(9.81)(1)

Consider the bar shown in (Figure 1). Neglect the thickness of the bar. Take AB Suppose that b1 ft. Figure 1 of 1 Sh Part A Determine the smallest coefficient of static friction at both A and B needed to hold the uniform 100lb bar in equilibrium. Express your answer using three significant figures. 195 . 41 Ivec 1 Submit Previous Answers Request

1. With respect to the architecture layered and kernel level, discuss windows and Unix OS architecture. 2. Discuss some 10 system call in windows and unix and its functionality, name, API etc.,

. Let X(e) denote the DTFT of a length9 sequence xn given by xn 3, 1, 5, 11, 0, 5, 3, 3, 8, 5n3. Evaluate the following functions of X(e) without computing the transform itself (a) X (e), (b) X(e), )X(e do, (d) X(e) do, I (e) I dx (ejo) do do.

The statespace model for a certain application has been given to us with the following state description matrices 0.174 0 0.157 0.645 1 000 0 000 000 000 100 01 0 0 C 1 0 0 0 0. B 0.207 0.005 0 0 0 (a) Draw a block diagram of the realization with an integrator for each statevariable. (b) A student has computed der C 2.3 x 107 and claims that the

A gas turbine powerplant is intaking 10 L/s of air at sea level (1 atm) with the density of 1.1 kg/m3. Compression ratio in compressor is 30:1. Kerosine is used as the fuel with the calorific value of 45 MJ/kg. At AFR (mass air/mass fuel ratio) of 70 the combustion efficiency is 80%. a) If thermal efficiency of the engine and generator efficiency

Calculate heat transport from one liquid to another liquid or through/past different surfaces. Sometimes we have to consider the heat transport from the theory of a heat exchanger. What are the conditions that force us to calculate the heat transport with the heat exchanger equations?

A centrifugal air compressor having a pressure compression ratio of S compresses air at the rate of 10 kgs. If the initial pressure and temperature of the air, is 1 bar and 20 C. find (i) the final temperature of the gas, and (ii) Power required to drive the compressor. Take y1.4 and cp1 kJkg K.

A cold heading operation forms the head on a steel nail. The strength coefficient for the steel = 500 MPa and the strain hardening exponent = 0.22. Coefficient of friction at the die-work interface = 0.14. The diameter of the wire stock for the nail = 4.0 mm. The nail head diameter = 10 mm, and its thickness = 1.5 mm. The final length of the nail

A single-pass rolling operation reduces a 20-mm-thick plate to 18 mm. The starting plate is 200 mm wide. Roll radius = 250 mm and rotational speed = 12 rev/min. The work metal has a strength coefficient = 600 MPa and a strain hardening exponent = 0.22. Determine (a) roll force, (b) roll torque, and (c) power required for this operation.

Sketch the root locus with respect to K for the equation 1 KG1H1(3) 0 and the following choices of G1H1(s). Be sure to give the asymptotes, arrival, and departure angles at any complex zero or pole, and the frequency of any imaginaryaxis crossing GH1(s) GH(s) (s s (s 2) (s 4s 68) 10) (s 4s 85) (s 1) 1 s (s 2) (s 3) Sketch the root

For the 3phase circuit given below, following phasors are known 1003230V Z 2230 and Vbc Draw following phasors in cartesian coordinates Vab, Vbc, Van, Vbn, Vcn, Ia, Ib, Ic la C Z n N N b,For the 3phase circuit given below, following phasors are known 1003230V Z 2230 and Vbc Draw following phasors in cartesian coordinates Vab, Vbc, Van,

A water pump is used to pump water from one large reservoir to another large reservoir that is at a higher elevation. The free surfaces of both reservoirs are exposed to atmospheric pressure, as given in the figure below. The pumps performance curve is approximated by the expression Havailable Ho aQ2, where the shutoff head Ho 50 m of water

When a light circuit containing several lights in parallel fails consistently, the fault might be: A. An overloaded circuit B. An under-loaded circuit C. The wattless power is too low D. The lamps have too low a watt rating

A feed pump of a binary vapour cycle is of centrifugal and delivers 20m at 750rpm against a dynamic head of 8m. Determine the power required to drive the motor, if the pump efficiency is 90%. If the max torque on the motor shaft is 30% more than the average torque, determine the diameter of the motor shaft. The permissible shear stress in the

Calculate the following quantities for the given three vectors A392 24, 72325, and C869385. a) A and unit vector b) 7x B c) X(B x0) a) 7 x (Bx)

When performing a meter base voltage check for a single phase, 3 wire, 240V meter, if voltage 120V is measured from each load side terminal to neutral, what should you do A. Good voltage, install meter B. Check for proper voltage on source side if OK, install meter C. Do not install meter, look for possible wiring problem or presence of a

A secondorder closed loop system is given by the transfer function. CR 10 s2 25 9 Determine the natural frequency, damping ratio, and damped natural frequency of the closedloop response. What is the steadystate output for a unitstep input. 5 marks

Determine the reactions at A and the tension in the string. The support at A restricts all translations and only the rotations about the y and zdirections. The 20 angle for the force F applied at E is in the xy plane, and the 30 angle is a rotation down towards the negative zdirection from the line ED. The magnitude of the applied force is F

Q How to differentiate thermodynamics and heat transfer?

Q Why are most of the gas containers cylindrical in shape?

The influences of temperature and impurities on resistivity of metals are given, in standard symbols, by Pipo a.T, the temperature 7 to be in C. Pi A c (1ci) (a) (b) Using the data provided in Fig. Q4, determine (i) The values of p, and a for pure copper (Cu) (ii) The values of A for nickel (Ni) as an impurity in copper and (iii) The electrical

Q Explain the role of Nitrogen in welding

Q Which gases can be used in place of nitrogen in welding?

Q Are the pneumatic system and the hydraulic system similar? Explain, how?

Q Why airplanes made up of thicker paper fly farther?

Q Can motor oil be used in a hydraulic system?

Q Is there any mechanical advantage of using a double pulley?

Implement the following equations as hazardfree circuits. Express these as Boolean algebraic equations in SOP form. Use Kmaps to determine where the potential hazards are. (2pts each) F(A,B,C) BCC G(A,B,C,D) m(0,4,5,6,7,9,11,13,14) H(A,B,C) (A B)(BC) I(A,B,C,D) M(0,1,3,5,7,8,9,13,15) J(A,B,C,D,E) m(0,1,3,4,7,11,12,15,16,17, 20, 28).,Implement

Assume that a threephase 4.16 kV wyegrounded feeder main has 4 copper conductors with an equivalent spacing of 37 in. between phase conductors and a laggingload power factor of 0.9. a. Determine the K constant of the main by employing Equation 4.77. b. Determine the K constant of the main by using the precalculated percent voltage drop per

A mass m (kg) at temperature T is cooling down until temperature T is theoretically reached. 00 The material has a specific heat capacity cp, (J kg K). The variation in temperature can be described by Eq. (1) with U and A the overall heat transfer coefficient (W m2 K) and the area for heat transfer (m) d (mc,T) UA(TT) dt If the specific heat

A hydrostorage plant uses a turbinepump which has 22,000 kW rated output capacity, with a plant use factor of 75. For 1.5hour peak, determine the hydraulic impoundment in cubic meter of water required. Friction loss in the penstock is 6 of gross head. Dam elevation is 120 ft, hydraulic turbine elevation is 40 ft and tail race elevation are 20 ft.

From the truss loaded as shown, solve for the following. a) Total reactions at the hinge and roller supports at A and H, respectively. (10pts) b) Magnitude and type of force on members AB, BD and BE by methods of joints. (20pts) c) Magnitude and type of force on members DF, EF and DE by method of sections. (30pts) 0.750k 2.50KN Lis 2.00m C 2.00m E

An electrical cartridge heater is used to heat water to a temperature of 50C in a manufacturing process. The heater is powered by 240V source and draws 15A of current. The length and diameter of the cartridge heater are 60cm and 1.5cm respectively. If the heater is immersed in the water such that the heat transfer coefficient is 4500 Wm K, find

Q What is the Otto cycle?

Q What type of computer programs a mechanical engineer can use in his/her work?

Q Which one has greater efficiency- A diesel engine or petrol engine with the same compression ratio?

Q Why is a thermostat used in the cooling system of engines?

Q What is the difference between total moisture and the inherent moisture of coal?

Q Name the different types of compressors used in a gas turbine?

Q What are the major and minor head losses in a fluid flow system?

Describe the microscopic mechanisms that are responsible for dislocation creep in metallic solids. How would you optimize the microstructure of the metal to resist dislocation creep 10 marks George Hapompwe was given instructions by the design engineer to be tightening bolts of a turbine casing to a prescribed torque after every 48 hours. After

Q Describe the superheating process?

Q What are the different types of cooling towers?

Q How can you differentiate between cast iron, mild steel, and high-carbon steel?

Q Give one drawback of supercritical boilers?

Q Why is the pneumatic system preferred over the hydraulic system?

Q Why are galvanised pipes not used for steam lines?

Q What is the reason for white smoke in two-stroke locomotive engines?

Investigate the concept of cavitation erosion in hydraulic machinery. How does cavitation lead to erosion, and what are the implications for the performance and durability of pumps and turbines? Discuss engineering strategies to mitigate cavitation erosion, considering both material selection and design modifications, and highlight challenges in

Discuss the intricacies of turbulent combustion in engineering applications. How does turbulence affect the combustion process, and what are the consequences for efficiency and pollutant emissions in combustion systems? Explore the challenges in modeling turbulent combustion, and propose engineering approaches to enhance combustion efficiency and

Explore the phenomenon of hydraulic jump in open-channel flows. How does a hydraulic jump occur, and what are the implications for energy dissipation and flow stability? Discuss the engineering applications of hydraulic jumps, challenges in predicting their occurrence, and strategies to control and optimize their effects in hydraulic systems.

Examine the role of cavitation in hydraulic systems and its implications for pump performance. How does cavitation occur, and what are the detrimental effects on pump components? Discuss the methods engineers employ to mitigate cavitation, considering both design modifications and operational adjustments.

Q Does stress produce strain or strain that produces stress?

Q Explain the difference between a rocket motion and a projectile motion?

Q Explain the difference between the turbine and the pump?

Q What is a periscope? Give its real-life application.

Consider a submerged, three-dimensional object in a non-uniform flow field. How does the variation in fluid velocity and density, along with the object's shape, influence the distribution of pressure forces on its surface? Provide insights into the mathematical expressions governing the pressure distribution in such a scenario, considering both

Explore the concept of fluid-structure interaction (FSI) in mechanical engineering applications. How does FSI occur, and what are the implications for the structural integrity of objects immersed in fluid? Discuss the challenges in simulating and analyzing FSI, and propose engineering strategies to design structures that can effectively withstand

2. Analyze an anisotropic fibrous composite to see how the anisotropy can be reduced in the manufacturing process. (40 points)

A Rogowski coil is used to measure lightning current. If the mutual inductance is 2mH, calculate the rate of change of current if the output voltage is 10V at the integrator and 1000V at the Rogowski coil. Find the current to be measured.