EF 152 Final Exam - Fall, 2016 Page 1 Copy 169

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1 EF 152 Final Exam - Fall, 2016 Page 1 Copy 169 The equation sheets may be removed when the test begins Instructions Do not open the exam until instructed to do so. Do not leave if there is less than 5 minutes to go in the exam. When time is called, immediately stop writing, remain seated, and pass your exam to the center aisle. Working after time is called results in an automatic deduction. Turn your equation sheets in with your exam. Guidelines Assume 3 significant figures for all given numbers unless otherwise stated Show all of your work no work, no credit Write your final answer in the box provided Include units for all answers Stress and Strain Universal Law of Gravitation Nm kg Satellites Bernoulli s Equation Continuity Kepler s Third Law m kg Atmospheric Pressure kpa 14.7 psi Density of Water 62.4 lb/ft 3 = 1000 kg/m 3 Conversions 1 ft 3 = 7.48 gal Ellipse Pressure in a fluid Buoyant force Stokes Law 6 Poiseuille s Equation Pa s Harmonic Motion sin cos ωcos ωsin sin ω cos tan Pendulum Simple: Physical: Sound Light Reflection: Refraction: Total Internal Reflection Wave Equation, Wave Speed Transverse Longitudinal String Frequencies Air Columns Closed Open n=1,3,5 n=1,2,3

2 EF 152 Final Exam - Fall, 2016 Page 2 Copy 169 Thermal Expansion Δ Δ Δ Δ Δ Heat Δ series 1 1 Conversions 1 cal = J 1 BTU = 1055 J Water Properties c = 1 cal/(g C) L f = 79.6 cal/g L v = 540 cal/g Work Isothermal: Adiabatic: 1 1 Ideal Gas Law Avogadro s number: 6.02x st Law Δ Efficiency 1 Otto: 1 Carnot: 1 Entropy Δ Δ Refrigerators EER = 3.413K Isobaric Q ncp T Isochoric Q nc Q W v T Adiabatic ΔQ = 0 pv constant TV 1 constant Adiabatic Tp 1 constant Constants m e = 9.109x10-31 kg m p = 1.673x10-27 kg m n = 1.675x10-27 kg k = 9x10 9 ε 0 = e = C (electron charge) ev = J Coulomb s Law; Electric Field Potential Energy; Potential 1 4 point charges parallel plates Resistors / Series Parallel Kirchoff s Rules Σ 0 for a closed loop Σ 0 for a junction R-C circuit time constant RC Capacitors / 1F 1C/1V parallel plates series parallel Magnetism straight wire

3 EF 152 Final Exam - Fall, 2016 Page 3 Copy 169 Name: Section: 1. Write your name and section above. Specify your EXAM ID below. Use 000 if you don t know your exam ID Digit #1 Digit #2 Digit #3 4. (1 pt) A 60 kip axial load is applied to a 60 ft concrete encased steel column. What is the same for both the concrete and the steel? (assume the concrete and steel are fully bonded) Stress Strain Force Modulus Area 5. (1 pt) An engineer floats in a river in a concrete boat. Which of the following is true? The volume of water displaced by the boat equals the volume of the boat The volume of water displaced by the boat equals the weight of the boat + engineer The weight of water displaced by the boat equals the volume of the boat + engineer The weight of water displaced by the boat equals the weight of the boat + engineer 6. (1 pt) Object A weighs 50 lb. Object B weighs 25 lb. How do their respective escape velocities compare? va = ¼ vb va = ½ vb va = vb va = 2 vb va = 4 vb 7. (1 pt) Professor Schleter drains his 4 ft deep swimming pool through a ½ hole in the bottom of the pool and it takes 18 hours. How long would it take to drain only the top half of the pool? Depends on the viscosity 9 hours More than 9 hours Less than 9 hours

4 EF 152 Final Exam - Fall, 2016 Page 4 Copy (1 pt) A steel ball is dropped into a tank of water to determine its terminal velocity. What s the correct FBD? 9. (1 pt) Two cars, each traveling at 30 mph, are approaching each other. From the first car, Dr. B yells Go Vols at a frequency of 6000 Hz. Prof Schleter, in the other car, will hear: a lower frequency the same frequency a higher frequency 10. (1 pt) A simple pendulum swings with a period of 2.0 seconds. How does the period change if the mass of the pendulum is decreased? The period is shorter The period is the same The period is longer 11. (1 pt) For an open pipe, which harmonic produces a wave whose wavelength is equal to the length of the pipe? First Second Third Fourth 12. (1 pt) A wire under tension vibrates with a frequency of 400 Hz. If the tension is doubled, what is the new frequency? 200 Hz 285 Hz 400 Hz 560 Hz 800 Hz 1600 Hz 13. (1 pt) Given two different mediums as shown, if θ 1 > θ 2, what is the relationship between the speed of light (v) in the two mediums? v1 < v2 v1 = v2 v1 > v2

5 EF 152 Final Exam - Fall, 2016 Page 5 Copy (1 pt) Given your experience of what feels colder when you walk on it, which of the surfaces would have the highest thermal conductivity? A steel surface A rug A concrete floor What feels colder has nothing to do with thermal conductivity 15. (1 pt) If you start with 1 gram of ice at 0 C and add 300 calories, what do you have? all ice at 0 C a mixture of ice and water at 0 C water at a temperature between 0 C and 100 C a mixture of water and steam at 100 C all steam at 100 C 16. (1 pt) Liquid A and Liquid B have the same mass, the same initial temperature, and are heated for the same time over the same stove. You measure the temperatures and find that Liquid A has a higher temperature than Liquid B. Which liquid has a higher specific heat? Liquid A Liquid B both the same 17. (1 pt) Given the diesel cycle shown above, what is the equation for the amount of heat added from B to C? Assume an ideal gas. ncˈp (T c -T b ) ncˈv (T c -T b ) 1 1

6 EF 152 Final Exam - Fall, 2016 Page 6 Copy (1 pt) Given that water > steel, what occurs when you heat a 4 L steel pot completely filled with 4 L of water by 10 C? Water expands more than steel; the pot will overflow 19. (1 pt) What are the units for capacitance? Steel expands more than water; the pot will not overflow Both materials expand the same amount Coulombs Ohms Farads Tesla Watts 20. (1 pt) For a copper wire (=3.9x10 3 C 1, =1.72x10 8 Ω m), what will increase its resistance? Increasing Length Increasing diameter Decreasing temperature 21. (1 pt) What does the C in the equation C = Q/V ab stand for? All of the above Coulomb Charge Capacitance Current 22. (1 pt) For particle P with a charge of +4 C, what is the direction of the electric field at point A? (see illustration for axis convention) P A y x +i -i +j -j +k -k 23. (1 pt) Write a correct loop equation for the clockwise L 1 for the circuit below. 10 I1 15 I1 40 I2 = 0 10 I1 15 I I2 = I1 40 I2 = I I2 = I1 40 I2 = I I2 = 0

7 EF 152 Final Exam - Fall, 2016 Page 7 Copy (8 pts) An engineer suspends a Christmas tree with two 2.5 mm diameter steel cables (breaking strength = 0.79 kn). T B, the tension in cable B, is 239 Newtons. Determine the weight of the tree and the minimum factor of safety in the cables. A free body diagram is required for full credit. T A T B W tree FS min 25. (8 pts) A small angled pipe 12 ft in length is connected to a large horizontal pipe as shown. At what velocity (v 2 ) will water exit the small pipe? Assume an ideal fluid. 2" diameter P g = 2 atm (up) 12 ft ¾" diameter exits to atmosphere v 2 =? 35

8 EF 152 Final Exam - Fall, 2016 Page 8 Copy (8 pts) A 3.9 kg mass is connected to a spring (k=155 N/m) and is sliding on a horizontal frictionless surface. The mass is given an initial displacement of +11 cm and released with an initial velocity of 29 cm/s. Determine the velocity of the mass at t=2.1 seconds. 27. (8 pts) According to Adam Larkey, the I CM for a 1.2 lb fiddle is 0.85 slug ft 2. If a fiddle is held vertically and allowed to oscillate about point P, what is the fiddle s frequency of oscillation (in Hz)? P 1.8 ft CM

9 EF 152 Final Exam - Fall, 2016 Page 9 Copy (8 pts) A speaker has a maximum power output of 10W. If the speaker is operating at its maximum, at what distance away is the sound level 91 db? I o = 1 x W/m (8 pts) A styrofoam cooler is filled with snow. Assume the inside of the cooler and the snow are at 0 C. The cooler sits outside on a 32 C day and 46 grams of snow melts in one hour. The cooler s walls have a thickness of m and a total surface area of 0.75 m 2. Determine the thermal conductivity of the cooler.

10 EF 152 Final Exam - Fall, 2016 Page 10 Copy (8 pts) The Lazydog Cycle of an unknown mass of gas is as follows: A B: heated at constant volume, V A, from 120 kpa to 400 kpa B C: adiabatic expansion to V C = 0.4 m 3 & a pressure of 180 kpa C D: cooled at constant volume from 180 kpa to 120 kpa D A: returned to the initial volume at constant pressure. Assume ideal diatomic gas with γ = 1.4. Determine the initial volume at V A. Determine the amount of work done during each cycle. V A = W cycle = Please turn to the next page

11 EF 152 Final Exam - Fall, 2016 Page 11 Copy (8 pts) A Carnot refrigerator removes 1200 Joules of heat. If the interior is at 10 C and the outside is at 35 C, how much heat is transferred to the outside? 32. (8 pts) What is the power dissipated by the 5 ohm resister in this circuit? Please turn the page for the final problem

12 EF 152 Final Exam - Fall, 2016 Page 12 Copy (8 pts) A charged particle with q= 6mC is moving with a velocity of (4500 ȷ ) m/s through a uniform magnetic field of (0.016 ı k ) T and a uniform electric field of (200 ȷ ) N/C. Determine the net force on the particle (Express the result in ı ȷ k notation)