NUPOC STUDY GUIDE Navy Recruiting Command NUPOC STUDY GUIDE Congratulations Right now you are faced with quite a challenge – an interview with the Division of Naval Reactors in Washington, D.C. It won’t be easy. A number of distinguished leaders, among them a former President of the United States, have gone through these interviews and have felt the same anxiety you may be feeling. Your recruiter will do everything he or she can to maximize your chances of being selected. This study guide contains the type of questions that you can expect to be asked during your interviews at Naval Reactors. It does not contain all questions that may be asked; however, it is representative of the types of problems that are most encountered at the interviews. The interview focuses on technical questions from Calculus, Physics, and other technical courses. The majority of the questions are from Calculus and Physics. You may be asked questions from other topics in your major. Keep in mind that the interviewer has a copy of your transcripts to use as a guide for these questions. A typical interview lasts 30-40 minutes and contains 2-4 major questions per interview. General Notes: The Navy pays for the hotel room for two nights, transportation to and from the airport, your plane ticket and your meals at the hotel. All other expenses are your responsibility. You will fly in the afternoon before the interview. The interview starts bright and early the next morning. You are free to spend the night in the hotel following the interview. You are welcome to stay the day after the interviews to see Washington, D.C. Discuss this with your recruiter, government tickets are easily changed. Things to Bring - Conservative suit (matching trousers and jacket) and tie for men, equivalent attire for women Airline ticket Carry-on luggage (don’t take the chance of losing checked luggage) Reading material (you will need it for time between interviews) Some cash (for tips, souvenirs, tours, etc.) Schedule: DAY BEFORE THE INTERVIEW 1200-1800 Fly into National Airport, check in the hotel 1800-1900 Dinner in hotel or in surrounding Crystal City establishments 2000 Relax!!! DAY OF INTERVIEW 0630-0700 Breakfast in hotel 0700 Meet recruiter in lobby for transportation to Naval Reactors 0730-1200 Technical interviews 1200-1300 Lunch 1300-1600 Interview with Admiral Donald. Following interview, return to hotel for swearing in and some administrative paperwork How to Use This Study Guide This guide is divided into several subjects. Everyone is expected to answer Calculus, Physics, and a portion of Electrical. Other subjects are dependent on your major. As the name of this document implies, it is only a guide. It is meant to focus on areas that are most often covered at the interview but in no way does it encompass all possible questions that could be asked of you. While Calculus and Physics are the main focus, any topics covered by courses that appear on your transcript are fair game for questions. To simulate the interview environment, you should sit down with the study guide, paper and a pencil. Answer the questions using the problem solving approach as discussed later. Using old textbooks or class notes check the answer or look up the solution. If you are still having difficulty, call your recruiter and he will get in touch with a Nuclear Trained Officer who can assist with these solutions. What Happens Next After having time to practice, you will be briefed in greater detail by one of the Nuclear Trained Officers (NTO). He will go into more detail on the interview process and will give a mock interview. You will meet the NTO on the VIP trip when these briefings and interviews occur. It is imperative that you complete a major portion of the study guide prior to the VIP trip. Technical Interview Details - minimum of two interviews (three interviews for NR Engineer Candidates) additional interviews may be given (random, question of the day or questionable performance on prior interview) 30-40 minutes in length first 10 minutes are usually personal questions given in the interviewers office interviewer is a senior design engineer interviews are staggered - no competition between applicants assess your ability to make it through Nuclear Power School all courses on transcripts are fair game with special emphasis on Calculus and Physics Technical Interview Hints - - all questions are given orally – be prepared to write use plenty of paper or blackboard and present ideas clearly take your time, the interviewer will speed you up if required make assumptions: do not ask for assumptions do not assume the problem away DO make the problem solvable use numerical approximations to make the math easier understand the question use the problem solving approach use applicable equations – do not ask if derivation is required do not volunteer information or lack of information do not expect help or additional information from the interviewer DO NOT give up unless told so by the interviewer ANSWER THE QUESTION WITH CONFIDENCE Personal Interviews This packet also contains the type of personal questions most often asked by Admiral Donald. You may also be asked some of these questions during the first 5-10 minutes of your technical interviews. Keep these in mind when answering them: - there is no one correct answer for everyone - you are the only expert on yourself - decide what is the best answer for you - be straight forward, honest and consistent - be as direct as possible with your answers The Interviews: Design engineers who work at Naval Reactors conduct the technical interviews in the morning. Most are civilians with specific areas of expertise. If you are an EE, you will interview with the EE’s (and most other candidates will interview with people of the same background). The interviews last thirty minutes to an hour a piece and are one on one. Most people have two technical interviews. Some may have a third interview. The only thing you need to bring to the interview is a writing instrument (paper will be provided by the interviewer). Interview Strategy: Consider the purpose of the Naval Reactors technical interviews. The interviewers are attempting to determine if you are the type of person who can be in charge of a nuclear power plant. For instructor candidates, are you dynamic enough to teach a wide range of technical subjects to extremely intelligent students? The interviewers are projecting you into these roles. When given a technical problem, use standard problem solving techniques (i.e. write down the problem with given information, known relationships, diagrams as necessary). Make sure that your answer is reasonable! Talk your way through the solution. This is very important. The interviewer is as interested in your thought processes as he is in your final answer. Also, an interviewer is more inclined to help you if you show some basic understanding and if he knows you may have problems. Anything on your transcripts is fair game. However, most questions will focus on calculus, physics and your major. Be positive! When asked about weakness on your transcript, acknowledge it and say what you have done about it. Answer thoroughly and expansively. Tie in your answers to fundamental principles. Show perseverance! Do not give up on a problem. NEVER, ever say, “I don’t know”. Uttering these words can prove fatal. Grades get you to the interview. They do not get you selected. Motivation and enthusiasm are as important as technical ability. Admiral Donald’s Interview: This man will determine in less than five minutes whether or not you will become a nuclear officer in the Navy. During your interview with him he will have three things in front of him: 1) your transcripts, 2) the evaluations from the technical interviews and 3) YOU. By the time you interview with the Admiral, there is nothing you can do about your previous interviews or your transcripts, but you have complete control over how you present yourself. First impressions are about the only thing you will leave him with, so they are extremely important. A firm handshake (if offered), strong voice and good eye contact are mandatory. He rarely asks technical questions. Remember, the Admiral will be trying to imagine you on the bridge of a warship or in control of a submarine (NUPOC), before a room of extremely competitive students (Instructor), or maintaining the impeccable design standards of Naval Reactors (NR Engineer). He asks most people “Why do you want to do this?” You should have an answer ready. Above all else, be honest and professional. Additional Areas to Study by Major All Majors: - Definitions of differentials, derivatives and integrals Integration by parts Double integrals Classify DEQs (and solve 1st and 2nd order linears) Polar/cylindrical/spherical coordinates Derive areas of circle, triangle, sphere (surface) Derive volume of sphere Definition of pH Types of chemical bonds Pascal’s Law Archimedes’ principle Simple DC RC & RL circuits Describe one of your old physics or chemistry labs Definitions and units for enthalpy and entropy Electrical Engineering: - Control systems (Nyquist diagrams, etc.) Motor/generator theory LaPlace transform solutions to RLCs Digital logic AC/DC circuit analysis Transformer theory Electromagnetic induction Faraday’s Law Mechanical Engineering: - Shear/moment diagrams for beams Stress/strain curves, typical values for Young’s Modulus of steel Types of welds Annealing, tempering, forging, cold working Heat transfer around boundary layers and through different types of materials (qualitative) Basic heat transfer problems for heat exchangers (Q=UA T, Q=mc T_ Tank draining problems (fluids with Bernoulli’s) Hooke’s law Laws of thermodynamics Moment of inertia Heat transfer equations (conduction, convection, and radiation) Chemical Engineering: - Concentration/dilution problems solved with DEQs Corrosion (how to minimize, what causes it) Buffers Types of bonds pH problems Equations for Gibbs Free Energy and Helmholtz Energy Catalysts Metals versus nonmetals Aerospace Engineering: - Resonant frequency Bernoulli’s Equation/fluids/transport problems Civil Engineering: - Tank draining problems (fluids with Bernoulli’s) Chemistry: - Types of bonds Buffers - Crystal structures pH problems Catalysts Metals versus nonmetals Computer: - Boolean algebra Semi-conductor theory Probs and stats Physics: - Elastic/inelastic collisions Orbit problems Momentum problems Math: - Linear algebra Taylor and Fourier series Triple integrals Decay/buildup problems using a series of DEQs Spherical coordinates Derive quadratic equation Questions for All Majors: - What assurance can you give that you will successfully complete Nuclear Power School (NPS)? - What are the hours of study required in your major as compared to the number required of an engineering (non-tech) major at your school? - Why were you so nervous in your interviews? - How did you pay for college? - What did you do during the unaccounted-for time on your transcript? - To what other schools did you apply? - In what extracurricular activities did you participate? - Discuss any summer jobs and school projects. - Is your school accredited? - How did your school/dept. compare with others? - Why are you a technical major when you do so much better in non-technical subjects? - Are you fully aware of what you will undergo at NPS? - How were you informed about NPS? - Do you feel that your preparation was adequate enough to get you selected? - Why did you choose to attend your college? - Why did you choose your major? - Why did you transfer schools (if applicable)? - How many hours per week do you study? - Why did you take more than 4 years to complete college? - Where are you from? - What do you do in your free time? - Why do I interview each applicant? - Tell me something about the program. - Why should I let you into the program? Mathematics, Calculus and Differential Equations 1. What is a solution to the equation (1-y)2 + 2xy = 0 A. (1,1) B. (1,i) C. (i,1) D. (1,0) 2. The locus of p(x,y), such that the difference of their distance from two fixed points is constant, a(n), is called: A. ellipse B. hyperbola C. parabola D. circle 3. A propeller plane and a jet travel 3000 miles. The velocity of the plane is 1/3 the velocity of the jet. It takes the prop plane 10 hours longer to complete the trip. What is the velocity of the jet? 4. What is the center of x2 + y2 – 2x – 4y – 17 = 0? 5. Simplify: a4 + b4 a2 + b 2 6. Simplify: 3 + 2i 3 – 2i 7. Solve a system of 3 simultaneous linear equations in three variables. 5x – 4y + 2z = 0 -3x + 4y =6 x + 4z = 6 8. What is a logarithm? How is e, the natural logarithm base, defined? 9. The number of square feet in a circle is equal to the number in feet of the circle’s circumference. What is the circle’s radius? 10. Derive the equation of a circle around any point. 11. Given a closed box, where the length is twice the height, the width is 10 meters less than the length, and the surface area is 10 times the width times the height, what are the dimensions? 12. Derive the quadratic equation. 13. What geometric surface encloses the maximum volume with the minimum surface area? How would you prove it? 14. What type of smooth curve would go through these points: (0,4), (2,0) and (-2,0)? What would its equation be? 15. Find the area of the following using Calculus and also derive the formulas for the volumes of C. and D.: A. Triangle B. Circle C. Pyramid D. Cone 16. Draw the following curves and find the area between them: A. y = 2 + e-x y = 1 + x2 B. y = x2 y=x 17. Plot f(x) = x2 + x – 6. Find the area between the x-axis in the top and the line on the bottom and the graph on each side. y = -4 18. Rotate y = 1/x about the x-axis and find the volume from 1 to infinity. 19. Determine the area between two concentric circles of radii 1 and 2 respectively, using calculus. 20. Integrate the following: A. ∫ (x sinx) dx B. ∫ x (x2 – 4) ½ dx C. ∫ e – 3/x dx x2 4 D. ∫ (e-x + 3x2) dx E. ∫ (x sin2x + x3) dx F. ∫ sec(u)tan(u) du G. ∫ xex dx H. ∫ (y + 3)(y + 1) dy R /2 /2 I. ∫ ∫ ∫ r sin()dddr 0 0 0 J. ∫ (2x + 1) dx 21. Take the derivative with respect to x of the following: A. cos4x sinx B. ae-bx cx2 C. 5x4 D. x (x2 – 4)1/2 E. Each of these: sin(x), cos(x), tan(x), cot(x), sec(x), csc(x) F. ln(x) and 10x G. x + x3 + sin(x)cos(x) + sin(x) H. x5 + (cos x)(ex) + sin(x2/3) I. x½ + x2sin2x 22. What is an integral? How is it used? What is the difference between a definite and an indefinite integral? 23. What is a derivative? How is it used? What is a differential? What is the significance of the first and second derivative? 24. Prove that the derivative of x2 is 2x. 25. What is limx0 sin(x)/x ? 26. Be able to integrate or differentiate by using parts, chain rule or quotient rule. 27. Draw the following curves. Plot any maximum, minimum, and points of inflection. A. B. C. D. E. F. f(x) f(x) f(x) f(x) f(x) f(x) = = = = = = 2 e-x a sinx e /2 3x2 – 17x –10 x3 – x2 xx G. f(x) = x2e(-x 2 ) 28. Analyze the curve y = 1 + e-x by finding the first two derivatives, maxima, minima and inflection points. 29. Find the maximum or minimum of a parabola and determine if it is a maximum or minimum. 30. Using Calculus, derive the formula for the exposed surface area of a ball floating in water. 31. Solve the following differential equations: A. y ’’ + 6y’ + 9 = 5 B. dN = -2N dt C. y’ = xy3 at x=0 and y=1 32. For the following curve, plot the first and second derivatives: y x 33. Given 80 feet of fencing, what is the maximum area that you can enclose along a wall? 34. Given the figure below, determine the value of x so when the corners are removed and flaps folded up, the five-sided box formed will have the maximum volume. L x x W 35. Two runners start at a distance of 10 miles from each other. They run towards each other at a constant velocity of 5 mph. A fly takes off from runner one’s nose at time zero. The fly has a constant velocity of 20 mph and flies between the runners. Find the total distance that the fly has traveled when the runners collide. 36. What is a Laplace transform, a Fourier transform or a Taylor series? How are each used? 37. When do you use L’Hopital’s Rule? 38. What is the probability of throwing one “7” with two dice? 39. If the population doubles in two years, how long does it take to triple? 40. Find f(x) which best describes the following graph. “A” represents area. y = f(x) y 3A 1A x 41. Use a first order differential equation to find the function to represent current with respect to time and to find the time constant of the circuit. t=0 R C V 42. Show how to solve a differential equation with matrices. 43. Find the sum of: 100 n n=1 44. Given the figure below with uniform mass, what is the y-coordinate of the center of gravity? a a a l 45. Describe how to classify differential equations. 46. Solve: x” + 5x’ + 6x = e-t 47. What is the Laplace transform of f(t) = t ? l 48. Solve: y” + 4y’ + 3y = sin(x) 49. Solve: dx/dt = x/k 50. Solve the general and specific homogeneous equation with derivatives: dy/dx + Ky = 10 51. Explain how to solve the following differential equation: A” + A’ + A = 0 52. Solve: y – 3y’ = 0 for y(0) = 3 Physics 1. What must the angle be in order for the block of mass M to start sliding? μ = 0.8 M θ 2. Find the final velocity of M for both elastic collision and inelastic collision m M v0 = 0 Vo 3. Describe the motion of the block-spring assembly when the block is displaced 4 inches from the equilibrium position. k M 4. How does the gravitational force vary between two masses if distance is doubled? How does the electrostatic force vary between two charged particles if the distance is doubled? Explain using both equations and physical applications. 5. Given the following diagram, calculate the distance traveled by the ball being thrown off the monument: Vo = 50 ft/sec 6. A spaceship is accelerating at 1000 m/sec2. How much force is required from the 555 ft to completely stop the spaceship? backthrusters D 7. Find h such that the car will make it around the loop without falling. Find x that occurs when the car impacts the spring. M x r h k 8. What angle will give the maximum range for a projectile neglecting air resistance? What would happen if air resistance occurred? 9. If a piece of paper is put on a full glass of water and inverted, what happens? Why? 10. Given a hollow and a solid cylinder of equal masses that are placed on an inclined plane. Also, both cylinders have equal radii. Which cylinder will reach the bottom of the plane first? 11. In the following diagram, find the position of the electron when it hits the screen. Will it hit the screen? What two variables can you change to determine where the electron will hit? (Assume that d and L are fixed) TV screen V0 d ed/2 12. Given the following data from a projectile, find the height of the parabola. t = 4 seconds h 300 ft 13. List and discuss Newton’s Laws of Motion. 14. A bullet with a mass of 10 grams and a velocity of 1000 m/sec imbeds in a wooden block with a mass of 1000 grams suspended by a rope. How high will the block swing in the vertical direction? 15. Given a rocket sled with initial velocity equal to v 0, find the total distance the sled v0 travels. u = 0.1 m = 1 kg θ 16. Find the time it takes to hit the ground? V0 h 17. A man has vo = 3 m/s and starts z feet behind a bus with v = 0 at time 0. The bus accelerates with a = 1 m/s2. Does he catch the bus? 18. A block of mass M1 is attached by string to a support. The block is raised to a height H and released. It then strikes a block of mass M2 on a frictionless surface. Find the velocity of the block M2, assuming a totally elastic collision. M1 M2 h 19. Given the following set-up, why will only one of the balls swing out? 20. A 10 gram bullet with a velocity of 1000 m/sec strikes a 100 gram block of wood initially at rest. What is their combined velocity? Can you work the problem using the principle of Conservation of Momentum? Conservation of Energy? 110g 100g 10g 21. What is momentum and how does it relate to Newton’s Second Law? 22. What is the maximum altitude reached? W = 100 lb v0 = 100 ft/sec v0 W 23. A mass is dropped from a height H. What is the velocity of the mass just before it hits the ground? 24. Consider the following pendulum system: a. If the bob is released from rest, what is the maximum velocity attained? b. What assumptions are made in the answer? c. What difference does it make if the system is in a vacuum? d. Suppose a second mass m was suspended at the lowest point, what would be the velocities of both masses after collision? e. What if the collision was non-elastic? Δh 25. Given a spring with the force displacement relationship F = ex, determine the energy required to move the block 3 units. x F 26. Define work, energy and power. Wave Properties & Oscillations 1. What is the oscillation period of a simple harmonic oscillator? 2. Derive the period of a simple pendulum. 3. Explain the difference between light and radio waves. 4. What is the relationship between frequency and wavelength? 5. What is the frequency of a 5 Å wavelength emission? 6. Contrast light and sound waves. How do they propagate energy? Do they travel at different speeds in different media? Why? 7. Define Doppler Shift. 8. Arrange the following electro-magnetic radiation in order of increasing frequency: Xrays, gamma rays, infrared radiation, and visible light. 9. State Snell’s Law. 10. Draw a picture of a fish in water and show where you would throw a spear to hit it. Where does the fish appear? Why? How do n and C relate to refraction? 11. Draw a concave and convex lens. What effect would each have on paraxial rays? Why? 12. What does a diffraction grating do, and what is it used for? Are there circumstances under which light must be considered a particle? When? Electrical Engineering / Electromagnetics 1. Plot voltage versus time and current versus time for the circuit with the following substitutions: A. Resistor R t=0 B. Capacitor C. Inductor A/B/C 2. Find the total current and voltage drop across R 1 for the following circuits. R1 R1 R2 R2 3. Which diagram uses the most power? Discuss advantages and disadvantages for each step. = 100 Watt Bulb 10V 10V 4. Explain how a transistor works. 5. Explain Kirchoff’s Laws. Give applications of Kirchoff’s Laws to simple circuits. 6. How does an electric motor work? 7. Find the relationships between Voltage (V), Current (i), and number of turns (n). n1 n2 V1 V2 i1 i2 8. Why are electrical transmission lines braided vice solid? 9. Describe the differences between electric and magnetic fields. Show what happens to an electron in each field. Could you derive an experiment to measure the force on the electron in a magnetic field? 10. Using Faraday’s Law, state the direction of current in the loop on the left. ω + V _ 11. There is a light bulb on a circuit. Another bulb is added in series. What is the wattage in the two bulbs? Is this the best way to add a bulb to this circuit? How could you add it differently? Would the bulbs be brighter? Why? 12. Graph voltage and current versus time after the switch is closed in the circuit below. C t=0 V 13. Draw a simple RLC circuit and find the voltage. 14. What is capacitance and inductance? 15. How can the current in a wire be determined without touching it? 16. Given a RC circuit, determine the energy stored in the capacitor, the energy dissipated by the resistor, and the total energy contributed from the battery. 17. Find IR in the circuit shown. 1V 1V 1V 1V 1V 1V IR 18. Graph I1 and I2 vs. time for the circuit below. I1 + V _ I2 19. What is the average of voltage over one and one-half cycles? V 20. Discuss the pros and cons of three phase sources. 21. What is the difference between impedance and resistance? 22. What are Maxwell’s Equations used for? 23. What did Faraday do? 24. Given a bar magnet, what does its field look like? Given a wire with electric current flowing in it, simulate the bar magnet’s field. Can you, in a laboratory, simulate the earth’s magnetic field? 25. Are there places on earth that might affect a ship’s transmitters, receivers, etc. more than other places? Where and Why? 26. Given three 1 ohm resistors, how many ways can they be arranged to form different resistances by using any number of the resistors (three max)? 27. Find I1, I2 and I3 in the circuits below. Is I2 > or < I1? Compare I3 and I1. What effect would an infinite or zero capacitance have in circuit 3? I1 I2 ~ V I3 ~ V ~ V 28. How would you go about proving that a group of series and/or parallel resistors are equivalent to a single resistor? 29. What are the properties of a diode and how does one work? 30. Describe in detail how a transistor works. Of what material is it constructed? How are impurity ions diffused into the material? What makes a transistor amplify? 31. Explain digital circuits. 32. How do you find the Thevenin equivalent of a circuit? 33. Find the equation for current in a series RL circuit and find the energy stored in the inductor. 34. Find the current in each branch of the circuit below. I1 R + I2 R V _ L C 35. Describe the difference between an AC and DC motor. 36. Describe the properties of synchronous and induction motors. 37. Given the separately excited DC motor, how do you increase the speed? What is the reverse EMF? + + Rf E + Ra Vg _ Varm _ _ 38. How does a transformer work? What sort of losses are involved? 39. Draw a capacitor and resistor in parallel and input a sine wave. What type of current will flow? 40. Explain the operation of and diagram a full wave rectifier. Graph the input and output. How can you filter the output to look more like a DC source? What are the trade-offs involved with this method? Using your method of filtering, do we lose maximum voltage or current? 41. Draw a simple oscillating circuit. What type of input would you use? What type of waveform would you get out? 42. Given the following AC delta circuit, what is IL if R1 = .5R2 = 2R3? What is IL if all resistances are equal? IL R1 R2 V V R3 V 43. How does an electrical generator work? 44. How does impedance change with frequency? How does current change with frequency? Graph current vs. frequency. At what frequency is the current a maximum? R = 1kΩ, C = 1 μfarad I V(t) ~ C R 45. Explain what happens to current in a DC motor during startup. What is the role of the armature resistance? 46. Explain the physics of semi-conductors. 47. Draw V(t) and I(t) with respect to time. Set up the differential equation to solve for current. R Vin L ~ C 48. The switch closes at t = 0 for 20 seconds. Calculate the temperature rise in the 1 kg of water. V = 12V, R = 10Ω + V _ R Chemistry 1. What is pH? 2. Determine the final pH and temperature when these two solutions are mixed together in a 3-liter container. Solution A: 2 liters, pH = 3, Temp = 80F Solution B: 1 liter, pH = 5, Temp = 40F 3. Why is pH important in materials selection? 4. Describe the Bohr model of the atom. Is it realistic? 5. How many grams of oxygen are needed to make Sodium Trioxide if 500 grams of sulfur is initially used? 6. If NaOH and H2SO4 mix, what results? 7. Given thermodynamic data on reactants + products of the reaction in question 6, compute ∆Hrxn 8. What is the atomic number of Na? What is the electron structure of Na? 9. You have NaOH and HCl. Will they react? If so what is the outcome? 10. How many moles of CO2 can be obtained from burning 3 moles of C3H3 in an abundance of O2? 11. State the mathematical expression for the pH factor of a solution. What is the pH of pure water? What happens to pH if the hydrogen ion concentration increases? How is the disassociation constant of water defined? What happens to the pH of water as its temperature increases? 12. Give an example of the use of a differential equation in chemistry. Solve the equation. 13. How do you determine if a reaction is exothermic or endothermic? 14. The half-life of a compound is 40 years. After 60 years, what percentage of the compound has decayed away? 15. Explain ionic bonding. 16. Define corrosion and describe some different forms of corrosion. 17. What is an acid? What is a buffer solution? 18. Draw a H2 molecule. What types of bonds are involved? Why doesn’t it fly apart? 19. How many grams of iron will one liter of a 3 M HCl solution dissolve? Thermodynamics 1. Draw and explain a typical Rankine cycle. Include a discussion of enthalpy and entropy changes. 2. Draw and explain a typical Carnot cycle. 3. List and discuss the laws of thermodynamics. 4. Given a closed, adiabatic room with an open refrigerator. At time zero, the refrigerator is plugged in. Plot the temperature of the room as a function of time. 5. At time zero, the knife switch of the circuit is shut. The tank of water is insulated and open to the environment at the top. Plot temperature at the bottom of the tank as a function of time. H2O R t=0 6. Discuss the advantages and disadvantages of using a superheated steam cycle. 7. Discuss various types of heat transfer. 8. Discuss heat exchangers for both counter-flow and parallel flow type exchangers. Which is more efficient? 9. In the following heat exchanger, all values of temperature can be read from . thermometers and mc can be read from a flow meter. List all assumptions and find mh . Th in Tc in ∙h m ∙c m Tc out Heat Exchanger Th out (hot leg) (cold leg) 10. A containment building encloses the space around a helium gas reactor. The gas reactor has initial temperature Ti and initial volume Vi. If the reactor cracks and mixes with the air of the containment vessel (volume = Vcont), find the resulting temperature of the containment building. 11. A tank of N2 is @ 2000 psig and 70F. If the temperature of the tank rises to 140F, find the pressure in the tank? 12. If you know how much heat a bar is putting out, what is the temperature at the center of the bar? 13. What is enthalpy? How is it measured? How is it used to calculate entropy? 14. What is entropy? How is it used? Machine “A” and machine “B” are performing the same task. Machine “A” is causing twice the entropy change of machine “B”. Which would you rather use and why? 15. Suppose you have a container full of gas and heat it up. What happens to temperature and pressure? Why? 16. Given two boxes of identical volume and temperature and filled with helium, is it possible to have different pressures? 17. You have 100 lbs of water with cp = constant. How much heat would need to be added to raise the temperature by 23 F? 18. What is temperature? What is heat content? 19. A rigid container is filled with a mixture of three gases: A, B and C. The pressure gage reads PT. The container is evacuated and filled with an amount of gas A equal to that in the original mixture. The gage now reads PA. This process is repeated for gases B and C with the pressure gage reading PB and PC respectively. How is PT related to PA, PB, and PC? What assumptions are made? 20. Draw a phase diagram for water. Show where solid, liquid and gas lie. What is the “triple point”? Where is the region of five ices? 21. Given the set-up in Figure 1, how much work will be done after part of the weight is removed, as shown in Figure 2, knowing only the height the piston rises? W1 W0 ∆h Ideal gas Ideal gas 1 2 22. a. If ds = 0, what can you say about the process? b. If ds < 0, what can you say about the process? c. If ds1 < ds2, what can you conclude about these processes? 23. Determine the heat transfer and temperature profile across a wall of homogeneous material and thickness L. The fluid film and heat transfer coefficients (h) are known. h1 t1 h2 ta tb t2 L 24. Heat is added to a block of ice thermally insulated from its environment. Graph the temperature increase of a unit mass of ice per unit heat added as it changes phase to vapor. 25. Given one pound of ice at 32 F, how much water at 200 F must be added to bring the temperature to 50 F? Assume the specific heat of water to have a constant value of 1 BTU/(lb-F). 26. What is a Mollier diagram? Mechanical Engineering 1. Explain how a steam generator operates. 2. Given a full tank car which holds 10000 gallons, an empty barge with a capacity of 30000 gallons, and a pump and hose connecting the two, what should we do to empty the oil from the car to the barge? The hose is attached to the bottom of the tank car, 15 feet above the barge. (Refer to air vents in your answer) 3. Why is there a pump in the basic Rankine Steam cycle? 4. Draw a gas turbine block diagram. 5. In the following diagram, the upper tank is filled with water and the lower tank is empty. Both tanks are sealed, both valves are shut and the pump is off. How would you transfer water from the upper to the lower tank? Pump h Valves 6. Knowing the work done by the steam flow, explain why this is not the power out of the nuclear reactor. Steam Generator Reactor Out In Pump Fluids and Buoyancy 1. What will happen to the scale reading as the mass is lowered? M 2. Find pressure as a function of time. At time t = 0, the water level is 2 feet. Crosssectional area is 8 ft2 for the top and 1 ft2 for the bottom. ∙ =3-t M 2 ft ------ ∙ M = t2 0 ft -----3. For a hydrofoil aircraft, why is turbulent flow preferable? 4. In the following simplified system, where is pressure the greatest? Heat Dissipater Condenser Heat Engine Pump 5. If the flow rate is increased by a factor of three, how does the pressure change at both points? 6. What is force F? F 9000 lbs Cross-sectional areas A = 9 in2 1 ft B = 900 in2 A B 7. A ball of diameter 10 cm and mass 10 grams is dropped in a container of water. The cross-sectional area of the container is 100 cm2. What is the change in the height of the water column? 8. The cross-sectional area of the siphon tube is constant. The fluid flows from tub 1 to tub 2. Determine the maximum height h that will still result in fluid flow. h Tub 1 Tub 2 9. The motor on a centrifugal pump is hooked up backwards, causing the impeller to spin the wrong direction. What will happen to the head vs. gpm curve? 10. Describe how a Venturi meter works and show how it can be used to calculate fluid flow (Bernoulli’s Eqn. and the Continuity Eqn.) 11. What happens to the water level with respect to the shore when the sailor throws the lead anchor overboard? 12. How far will the water shoot out? h1 d h2 13. Explain how you would estimate the flow rate in a pipe. 14. If the liquid is flowing in the direction indicated, at what point is the pressure greatest? B A C D E 15. Given a fluid flowing through a pipe in the direction indicated, what difference in parameters exists between points A and B? A B 16. What is meant by laminar and turbulent flow? If you had a piping system, which type of flow would be better and why? 17. Which will raise the water level in a tank higher when added – a one pound block of iron or a one pound block of wood? Materials and Civil Engineering 1. Draw and explain a stress-strain curve for steel. Where is the elastic limit? The yield point? What are stress and strain? How would work be defined on the stress-strain curve? 2. Compare and contrast a stress-strain curve for steel with a similar curve of concrete. 3. What effect does varying pH have on metals? 4. Why is glass more difficult to break when it has been tempered? Describe what occurs within the glass. 5. What is “Young’s Modulus”? What is its approximate value for steel? 6. Describe the pros and cons of castings versus forgings. 7. Given an I beam, what types of forces are acting at the point of load on this beam? How do you find these forces? 8. Draw the shear and moment diagrams for this beam. C L 9. Define the following and explain what quantities they compare. (Give units where applicable) a. Hooke’s Law b. Poisson’s Ratio 10. Define “cold working”. What goes on within the material? What happens during “annealing”? Give physical properties. 11. Draw the shear and moment diagrams for this uniformly loaded beam. y W (lb/ft) x Statics/Dynamics 1. Find the forces in the following members of this truss: AB and BC. Dimensions are variable. Discuss tensile or compressive stresses. B A .∙ C W 2. What is the largest mass the following beam can hold before it breaks? List any assumptions. m l 3. Find R1 and R2 (Reactions). L/6 2/3 L F W R1 R2 L 4. How far does the man have to walk down the beam in order to tip the beam off fulcrum A? 150 lbs 50 lbs B A 5’ 10 ’ ’ 25 lb/ft 15 ’ 5. a) Find the tensions in the two ropes. A B W b) Now describe the forces on the block. A B W H2O 6. Given the figure below what conditions must be fulfilled in order for the system to remain in equilibrium? What is the largest value of ‘a’ that will still allow the system to remain in equilibrium? State assumptions. 10 ft ‘a’ 1 lb 10 lbs F1 6 ft F2 7. Given a block and tackle system and a known weight, give the magnitude of the forces at the numbered points. 1 4 3 100 2 8. How much would the 1 kg mass raise the 50 kg mass in the figure below? 1 50 9. What is a moment arm? 10. Express T in terms of L, W, and a. T L a W 11. A sliding block slows from 16 m/sec to 8 m/sec in two seconds. If it weighs B kg, what is the coefficient of sliding friction? 12. A car traveling at an initial velocity of v0 applies its brakes to come to a stop. The coefficient of friction is μ. What distance is required to stop? 13. A wheel rotating at an initial angular velocity of ω0 is accelerated to a final velocity of ωf after 10 revolutions. What is the angular acceleration? 14. A person is standing on a building of height h. He throws a ball out with velocity v0 at an angle θ to the horizon. How long will it take to reach the ground? 15. What is the velocity of the 50 lb block? (Massless, frictionless pulley) 35 lbs 16. If the thread is pulled in the direction shown, which way will the spool roll? 50 lbs F 17. Given the diagram below, what are the resultant force, velocity, and acceleration with respect to time? Fx 18. What forces act on an object in orbit? Why does the object stay in circular orbit? 19. What is the acceleration of the larger mass? (Pulley and rope are massless) 10 lbs 15 lbs 20. Given a particle in a circular orbit, give the horizontal component of its velocity. Give its position at any time t along the x-axis. 21. Given a coefficient of friction equal to μ, what force must be applied in order to move the block? F θ W 22. Derive F = ma. 23. Describe inertia. 24. Given μ = .3 on all surfaces, what is T in order to move the middle block? m1 m2 T m3 25. A ball is suspended at height h0. At t = 0, it is released and the following force is applied in the upward direction. a. Find an expression for h(t). b. Find a value for K such that the ball just touches the ground. F(t) slope = K h0 t (sec) 26. Find the position of the block as a function of time for both cases: - friction - frictionless M θ 27. Find the maximum acceleration of a truck that can occur such that the block remains on the truck bed. Mass of block = m μs = 0.3 μk = 0.1 28. A block falls on a conveyer belt with coefficient of friction μk. How long until the block gets moving 10 m/s? Atomic and Nuclear 1. Explain the possible energy levels for X-rays (discrete or continuous). 2. What is the Schrodinger wave equation? What is it used for, and what information about the hydrogen atom can it be used to determine? 3. Given a substance (plasma) which must be sustained at a high temperature, how would you do it? 4. What is Buckling? 5. What does a pressurizer do? Why is it important? 6. Draw a block diagram of a nuclear reactor? 7. Define fission and fusion. What are their differences? How does a breeder reactor work? 8. What is criticality? What is the neutron multiplication factor? Write and explain the four factor formula. 9. What is binding energy? How does this relate to nuclear power? 10. What happens to a PWR (pressurized water reactor) as the temperature increases? 11. Explain the difference between a PWR and a BWR (boiling water reactor). Sketch a primary and secondary loop for a PWR. 12. Describe how radiation is stopped by shielding. What types of material are best for various types of radiation and why? Other Questions 1. What is the ratio of change of the length of the shadow and what is the velocity of the shadow? 3 m/s 2. You have a car and a balloon is tied to the passenger seat. If you go from rest what happens to the balloon? 4 3. What is a neutron, alpha particle, and beta particle. Draw2 a H nucleus. 4. What are the four forces on an airplane? How is lift generated? 5. Pick a course you liked and show me something? 6. Find at what height the water will go if steady or if it will all draw out? Q = constant h0 2Q @ t = 0 7. How much force do you need at P to hold up the block? 8. The winch on the 10-ton barge slowly pulls in the line. How far has each barge moved when they are 25 feet apart? . 10 T . 50 ’ 15 T