EF 152 Final Exam - Fall 2006, Page 1 of 7, Name: Section: Exam Overview: a) The exam consists of 12 questions worth 8 points each (you get 4 points for putting your name and correctly identifying your section number A1, A2, B1, B2, or C1 on each page) b) Show all of your work c) Include FBD and KD where appropriate d) Include units for all answers which require units e) Include the correct number of significant digits f) Write your final answer in the space provided R Units 1.987 Btu/(lb mole. R) 1.987 cal/(mole. K) 0.730 atm. ft 3 /(lb mole. R) 10.73 psia. ft 3 /(lb mole. R) 1545.0 (lb/ft 2 ). ft 3 /(lb mole. R) 1.314 atm. ft 3 /(lb mole. K) 82.06 atm. cm 3 /(mole. K) 0.082 L. atm/(mole. K) 0.083 L. bar/(mole. K) 8.31 J/(mole. K) Constants and Conversions: g = 9.81 m/s 2 = 32.2 ft/s 2 ρ water = 1000 kg/m 3 C water = 1 cal/g-k 1 cal = 4.186 J 1 L = 1.0 x 10-3 m 3 Other constants will be given in individual problems as needed.
EF 152 Final Exam - Fall 2006, Page 2 of 7, Name: Section: 1) The 55 kg cylinder has an initial angular velocity of 35 rad/s clockwise (CW) as shown when it is brought into contact with the surface as point C. Due to friction at point C, the cylinder will slow down (the coefficient of kinetic friction is μ k = 0.25). How long does it take for the cylinder to stop spinning? Note, the link AB prevents the cylinder from translating, but does not prevent it from rotating. 2) A horizontal circular platform has a weight of 325 lb. The platform is free to rotate about the z axis and is initially at rest. A 155 lb man, also initially at rest, begins to run along the edge of the platform in a circular path of radius 10.0 ft. The man reaches a speed of 4.55 ft/s and then maintains that speed. Determine the angular velocity of the platform.
EF 152 Final Exam - Fall 2006, Page 3 of 7, Name: Section: 3) The cable AB is made of steel (US = 500 MN/m 2, E = 210,100 MN/m 2 ) and has a cross-sectional area of 1.5 cm 2. The distributed load has a peak value of 2000 N/m and is only on the center span. What is the Safety Factor for cable AB? Assume 3 Significant Figures for all numbers. D 4) For the structure in problem 3 above, assume that all the connections are pin connections (i.e., it is a Truss). What is the force in member AD (use T for tension, C for compression).
EF 152 Final Exam - Fall 2006, Page 4 of 7, Name: Section: 5) When a mass of 180 g is attached to a vertical spring and lowered to its equilibrium position, it is found that the spring extends 12 cm. If the mass is now displaced from its equilibrium position, what is the period of the resulting oscillations? 6) A simple pendulum of length 2.00 m is used to measure the acceleration of gravity at the surface of a distant planet. If the period of such a pendulum is 6.00 s, what is the acceleration of gravity?
EF 152 Final Exam - Fall 2006, Page 5 of 7, Name: Section: 7) Crude oil with a specific gravity of 0.920 is pumped at 1.50 m/s through a pipe with an inside diameter of 1.00 m. What value will the viscosity of the oil have to be to have to insure it is in turbulent flow in the pipe? 8) What is the Bernoulli equation? Describe it physically and mathematically, explain what assumptions were used in its development and why it is so important in engineering calculations.
EF 152 Final Exam - Fall 2006, Page 6 of 7, Name: Section: 9) Compare the van der Waals equation of state to the ideal gas law discussing the assumptions made in developing the ideal gas law and explaining how the van der Waals equation improves on the performance of the ideal gas law. Give specific examples of were and how the van der Waals equation is superior. 10) Two bulbs of equal volume are evacuated and connected by a tube of negligible volume. One bulb is placed in a 200.0 K constant temperature bath and the other is a 300.0 K bath, and then 1.00 moles of an ideal gas is injected into the system. Find the final number of moles in each bulb.
EF 152 Final Exam - Fall 2006, Page 7 of 7, Name: Section: 11) A gas undergoes a process from state 1 to state 2 that traces a straight line on a p-v diagram. At state 1 the gas has a pressure of 75 kpa and a volume of 12 m 3. At state 2 the pressure is 60.0 kpa and the volume is 20.0 m 3. The heat gained by the gas in this process is 600.0 kj. The internal energy of the gas at state 1 is 70.0 kj. What is the internal energy of the gas at state 2? 12) A Carnot engine operates between 350.0 K and 600.0 K. The engine delivers 10.0 kj of work in each cycle. How much heat is extracted from the 600.0 K reservoir in one cycle?