Master Engineering with Fun Quizzes & Brain Teasers!

The pipe carrying feed water to a boiler in a thermal power plant has been found to vibrate violently at a pump speed of 800 rpm. in order to reduce the vibrations, an absorber consisting of a spring of stiffness k, and a trial m, mass of 1 kg is attached to the pipe. this arrangement is found to give the natural frequency of the system as 750 rpm. it is desired to keep the natural frequencies of the system outside the operating speed range of the pump, which is 700 rpm to 1040 rpm. determine the new values ka, and ma, that satisfy this requirement.
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Steam enters an adiabatic turbine at 10 mpa and 500c and leaves at 10 kpa with a quality of 90 percent. neglecting the changes in kinetic and potential energies, determine the mass flow rate required for a power output of 5 mw.
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Type the exact building code that jerry will refer for the given scenario. jerry is in charge of installing heating, ventilating, and air-conditioning systems (hvac) to control environmental conditions in a building. he needs to be fully aware of the code
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Technician a says that since north american clutch manufacturers no longer use asbestos there is no need to be concerned by clutch dust. technician b says that compressed air is the best way to clean the clutch housing when performing a clutch replacement. who is correct?
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Water is the working fluid in a Rankine cycle. Steam enters the turbine at 1400 lbf/in. 2 and 1000F. The condenser pressure is 2 lbf/in. 2 Both the turbine and pump have isentropic efficiencies of 85%. The working fluid has negligible pressure drop in passing through the steam generator. The net power output of the cycle is 1 109 Btu/h. Cooling water experiences a temperature increase from 60F to 76F, with negligible pressure drop, as it passes through the condenser. Determine for the cycle (a) the mass flow rate of steam, in lb/h. (b) the rate of heat transfer, in Btu/h, to the working fluid passing through the steam generator. (c) the thermal efficiency. (d) the mass flow rate of cooling water, in lb/h
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A(n) (blank) on the head of the piston is frequently usedto indicate piston pin offset and the front of the piston
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What is a renewable energy ?
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Technician a says that main bearing oil clearance can be checked with plastigage. technician b says that main bearing oil clearance can be checked with a dial bore gauge. who is right?
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A house has an electric heating system that consists of a 300-W fan and an electric resistance heating element placed in a duct. Air flows steadily through the duct at a rate of 0. 66 kg/s and experiences a temperature rise of 7C. The rate of heat loss from the air in the duct is estimated to be 300 W. Determine the power rating of the electric resistance heating element. The constant pressure specific heat of air at room temperature is cp = 1. 005 kJ/kgK
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Tech a says that when replacing the clock spring, you should turn it all the way to either end and then install it in the steering column. tech b says that clock springs are used to return the steering wheel to its centered position. who is correct
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For the Elliptic curve E11(1, 6), consider the point G = (2, 7), compute the point 4G and 7G
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05] Assume a digital communication system with the following specifications: Pbe=0. 05, (n,k) block coding with n=20 and k-bit in every message, and the block code can correct maximum of 3 bits in every received dataword. Find the following: (a) The average number of errors in every transmitted codeword. (b) The number of packets received in error from 20000 transmitted packets. [2 marks]
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In 1859 two Frenchmen built the first machine-powered submarine. What powered the engine?pistonsforceturbinespressure
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For the last 10 years, am-mex coal has used the cost depletion factor of $2,500 per 100 tons to write off the investment of $38 million in its pennsylvania anthracite coal mine. depletion thus far totals $24.8 million. a new study to appraise mine reserves indicates that no more than 910,000 tons of salable coal remains. the estimated gross income is expected to be $8.8 million on a production level of 72,000 tons.determine next years depletion amount. the percentage depletion allowance is 10%. (enter your answer in dollars and not in millions.)the next year's depletion amount is $
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A manufacturing process that unintentionally introduces cracks to the surface of a part was used to produce load-bearing components. The design requires that the component be able to withstand a stress of 450MPa. A component failed catastrophically in service. You are asked to do a failure analysis to determine whether the component failed due to an overload in service or flaws from the manufacturing process. The manufacturer claims that the components were polished to remove the cracks and inspected to ensure that no surface cracks were larger than 0. 5mm, which means the component could stand a stress greater than 450MPa. The manufacturer believes the component failed due to operator error. It has been independently verified that the 5cm diameter cylindrical part was subjected to a axial tensile load of 1x106N. The component is made from a material, which has a fracture toughness of and an ultimate 75????Pamtensile strength of 600MPa. Assume Y=1. 12 for the external cracks. Who is at fault for the component failure, the manufacturer or the operator, or both? Show your work to support your answer
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For modeling and calculation purposes, architects treat air as an incompressible fluid. As an architect's intern, you are doing the specs on a dorm air conditioning system that is designed to replace the air in each room every twenty-nine minutes. If the rooms each have a volume of 175 m3 and they are supplied by ducts with a square cross section, determine the following. (a) the length of each side of a duct if the air speed in the duct is to be 3. 2 m/s m (b) the length of each side of a duct if the air speed at the duct is to be a value twice this speed. M
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State the size of the total drag force when the car is travelling at constant speed
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A flow of 12 cusecs enters 600 acres reservoir. Determine the time in hours required to raise water level by 6 inches?
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Consider the tube and inlet conditions of Problem 1. 30 Heat transfer at a rate of 3. 89 MW is delivered to the tube. For an exit pressure of p 8 bar, determine (a) the temperature of the water at the outlet as well as the change in (b) combined thermal and flow work, (c) mechanical energy, and (d) total energy of the water from the inlet to the outlet of the tube. Hint: As a first estimate, neglect the change in mechanical energy in solving part (a). Relevant properties may be obtained from a thermodynamics text
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What are the conditions and measures to ensure safety of food from production to consumption.
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An airplane would not be able to fly if it did not have a propeller. Why not? Support your answer with evidence from the text. What gives an airplane a forward force?
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The recommended welding lens shade number for use in each of the following or cutting processes
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Assume the small electronic computer is needed for data processing in an engineering office and the computer can be leased for $50 per day which includes the cost of maintenance or purchased for $25,000, the computer is expected to have a useful life for 15 years with salvage valise of $4000 at the end of that year. Its estimated that annual maintenance cost will be $2,800 if the interest rate is 9% and it cost $50 per day to operate the computer advise management on what choice to make
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Our space program requires a portable engine to generate electricity for a space station. It is proposed to use sodium (Tc 2300 K; Pc 195 bar; 0; CP/R 2. 5) as the working fluid in a customized form of a "Rankine" cycle. The high-temperature stream is not superheated before running through the turbine. Instead, the saturated vapor (T 1444 K, P sat 0. 828 MPa) is run directly through the (100% efficient, adiabatic) turbine. The rest of the Rankine cycle is the usual. That is, the outlet stream from the turbine passes through a condenser where it is cooled to saturated liquid at 1155 K (this is the normal boiling temperature of sodium), which is pumped (neglect the pump work) back into the boiler. (a) Estimate the quality coming out of the turbine. (b) Compute the work output per unit of heat input to the cycle,
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