Engineering

Consider a room with dimensions as in the sketch. Assuming all emissivities of surfaces are equal to 0.9, calculate the radiative heat transfer between the floor and the ceiling, if you know the surface temperature of the floor equal to 25o C and the surface temperature of the ceiling is equal to 10o C
2 Answers
Consider a steam turbine, with inflow at 500oC and 7.9 MPa. The machine has a total-to-static efficiency ofts=0.91, and the pressure at the outflow is 16kPa. Power extracted by the turbine is 38 MW. Assuming heat transfer and kinetic energy in the machine is negligible, find the mass flow rate and static enthalpy at the outflow.
1 Answer
g Doublereciprocal, or LineweaverBurk, plots can reveal the type of enzyme inhibition exhibited by an inhibitor. Competitive inhibitors increase the K M without affecting the V max . Noncompetitive inhibitors decrease the V max without affecting the K M . Uncompetitive inhibitors decrease both the K M and V max . A Lineweaver Burk plot shows two lines representing the kinetics of an enzyme with and without inhibitor. The x-axis plots the inverse of the substrate concentration, and the y-axis plots the inverse of the reaction velocity. The x-intercept of the line with inhibitor is more negative than the line with no inhibitor. Both lines have the same y-intercept. Based on the LineweaverBurk plot, what type of enzyme inhibition is exhibited by the inhibitor? competitive noncompetitive uncompetitive cannot be determined
1 Answer
A solid titanium alloy [G 114 GPa] shaft that is 720 mm long will be subjected to a pure torque of T 155 N m. Determine the minimum diameter required if the shear stress must not exceed 150 MPa and the angle of twist must not exceed 7?. Report both the maximum shear stress ? and the angle of twist ? at this minimum diameter. ?Part 1 where d is the shaft diameter. The polar moment of inertia is also a function of d. Find Incorrect. Consider the elastic tors on formula. The maximum shear stress occurs at the radial location ? = (d 2 the value of d for which the maximum shear stress in the shaft equals 150 MPa. Based only on the requirement that the shear stress must not exceed 150 MPa, what is the minimum diameter of the shaft? dr 16.1763 the tolerance is +/-2% Click if you would like to Show Work for this question: Open Show Work Attempts: 1 of 3 used SAVE FOR LATER SUBMIT ANSWER Part 2 Based only on the requirement that the angle of twist must not exceed 7, what is the minimum diameter of the shaft?
1 Answer
A 2-m3 rigid tank initially contains air at 100 kPa and 22C. The tank is connected to a supply line through a valve. Air is flowing in the supply line at 600 kPa and 22C. The valve is opened, and air is allowed to enter the tank until the pressure in the tank reaches the line pressure, at which point the valve is closed. A thermometer placed in the tank indicates that the air temperature at the final state is 77C. Determine (a) the mass of air that has entered the tank and (b) the amount of heat transfer
1 Answer
The primary mirror of a large telescope can have a diameter of 10 m and a mosaic of 36 hexagonal segments with the orientation of each segment actively controlled. Suppose this unity feedback system for the mirror segments has the loop transfer functionL(s) = Gc (s)G(s) = K / s(s^2 + 2s + 5) . (a) Find the asymptotes and sketch them in the s-plane. (b) Find the angle of departure from the complex poles. (c) Determine the gain when two roots lie on the imaginary axis.(d) Sketch the root locus.
1 Answer
Calculate the modulus, in GPa, of the bar of a steel alloy that has a measured stress of 321 MPa corresponding to a measured strain of 0.00155 in the linear elastic portion of the curve. Round answer to 3 significant figures and report answer in the format: 123 GPa
1 Answer
Imagine two tanks. Tank A is filled to depth h with water. Tank B is filled to depth h with oil. Which tank has the largest pressure? Why? Where in the tank does the largest pressure occur?
1 Answer
It takes a resistance heater having 2 kW power to heat a room having 5 m X 5 m X 6 m size to heat from 0 to 33 oC at sea level. Calculate the amount of time needed for this heating to occur in min (Please take Patm=101 kPa, give your answer with three decimals, and do NOT enter units!!!).
1 Answer
A photovoltaic panel of dimension 2m4m is installed on the roof of a home. The panel is irradiated with a solar flux of GS =700W /m2, oriented normal to the top panel surface. The absorptivity of the panel to the solar Irradiation is s =0.83, and the efficiency of conversion of the absorbed flux to electrical power is P /sGsA =0.5530.001Tp, where Tp is the panel temperature expressed in Kelvins and A is the solar panel area. Determine the electric power generated for a. A still summer day, in which Tsur =T[infinity]=35C, h=100W /m2 K, and b. A breezy winter day, for which Tsur =T[infinity]=15oC, h=30W /m2 K. The panel Emissivity is 0.90.
1 Answer
Choose the best data type for each of the following so that any reasonable value is accommodated but no memory storage is wasted. Give an example of a typical value that would be held by the variable, and explain why you chose the type you did.a. the number of siblings you haveb. your final grade in this classc. the population of Earthd. the population of a U.S. countye. the number of passengers on a busf. one player's score in a Scrabble gameg. one team's score in a Major League Baseball gameh. the year an historical event occurredi. the number of legs on an animalj. the price of an automobile
2 Answers
The presence of free oxygen in the atmosphere is attributed mainly to Volcanic activity Development of plant life, especially algae Formation of the inner core Formation of the outer core
1 Answer
Two soils are fully saturated with liquid (no gas present) and the soils have the same void ratio. One soil is saturated with water and the other is saturated with alcohol. The unit weight of water is approximately 1g/cm3 while that of alcohol is about 0.8 g/cm3. Which soil sample has the larger water content? Why?
2 Answers
2. The initially velocity of the box and truck is 60 mph. When the truck brakes such that the deceleration is constant it takes the truck 350 ft to come to rest. During that time the box slides 10 ft and slams into the end of the truck at B. If the coeff of kinetic friction is 0.3, at what speed relative to the truck does the box hit at B? Ans: 5.29 ft/s.
1 Answer
In order to test the feasibility of drying a certain foodstuff, drying data were obtained in a tray dryer with air flow over the top exposed surface having an area of 0.186 m2. The bone dry sample weight was 3.765 kg dry solid. At equilibrium after a long period, the wet sample weight was 3.955 kg (water plus solid). Hence, 3.955-3.765 or 0.190 kg of equilibrium moisture was present. The following table provides the sample weights versus time during the drying test: Time (hr) Weight (kg) Time (hr) Weight (kg) Time (hr) Weight (kg) 0 4.944 2.2 4.554 7.0 4.019 0.4 4.885 3.0 4.404 9.0 3.978 0.8 4.808 4.2 4.241 12.0 3.955 1.4 4.699 5.0 4.150 A) Calculate the free moisture content, X (kg water per kg dry solid) for each data point and plot X versus t; B) Using the slope, calculate the drying rate, R in kg water per hour per square meter and plot R versus X; C) Using this drying rate curve, predict the total time to dry the sample from X = 0.20 to X = 0.04. Use numerical integration in the falling rate period. What is the drying rate in the constant rate period and what is X in the constant rate period?
1 Answer
Your program will be a line editor. A line editor is an editor where all operations are performed by entering commands at the command line. Commands include displaying lines, inserting text, editing lines, cutting and pasting text, loading and saving files. For example, a session where the user enters three lines of text and saves them as a new file may appear as:
1 Answer
Design a circuit with output f and inputs x1, x0, y1, and y0. Let X = x1x0 and Y = y1y0 represent two 2-digit binary numbers. The output f should be 1 if the numbers represented by X and Y are equal. Otherwise, f should be 0.
1 Answer
In a tensile test on a steel specimen, true strain = 0.12 at a stress of 250 MPa. When true stress = 350 MPa, true strain = 0.26. Determine the strength coefficient and the strain-hardening exponent in the flow curve equation.
1 Answer
214Bi83 --> 214Po84 + eBismuth-214 undergoes first-order radioactive decay to polonium-214 by the release of a beta particle, as represented by the nuclear equation above. Which of the following quantities plotted versus time will produce a straight line?(A) [Bi](B) [Po](C) ln[Bi](D) 1/[Bi]
2 Answers
An AISI 1040 cold-drawn steel tube has an OD 5 50 mm and wall thickness 6 mm. Whatmaximum external pressure can this tube withstand if the largest principal normal stress is notto exceed 80 percent of the minimum yield strength of the material?
1 Answer
. A 10W light bulb connected to a series of batteries may produce a brighter lightthan a 250W light bulb connected to the same batteries. Why? Explain.
2 Answers
StackOfStrings s = new StackOfStrings(); while (!StdIn.isEmpty()) { String item = StdIn.readString(); if (!item.equals("-")) s.push(item); else if (s.isEmpty()) StdOut.println("BAD INPUT"); else StdOut.print(s.pop() + " "); }
1 Answer
A vertical plate has a sharp-edged orifice at its center. A water jet of speed V strikes the plate concentrically. Obtain an expression for the external force needed to hold the plate in place, if the jet leaving the orifice also has speed V. Evaluate the force for V 5 15 ft/s, D 5 4 in., and d 5 1 in. Plot the required force as a function of diameter ratio for a suitable range of diameter d.
2 Answers
Problem 6.3 720 Consider a hot automotive engine, which can be approximated as a 0.5-m-high, 0.40-m-wide, and 0.8-m-long rectangular block. The bottom surface of the block is at a temperature of 80C and has an emissivity of 0.95. The ambient air is at 20C, and the road surface is at 25C. Determine the rate of heat transfer from the bottom surface of the engine block by convection and radiation as the car travels at a velocity of 80 km/h. Assume the flow to be turbulent over the entire surface because of the constant agitation of the engine block
2 Answers