A prototype of a part is to be fabricated using stereolithography. The part is shaped like a right triangle whose base = 36 mm, height 48mm, and thickness = 30 mm. In the stereolithography process, the layer thickness = 0.15 mm. Diameter of the laser beam spot = 0.40 mm, and the beam is moved across the surface of the photopolymer at a velocity of 2200 mm/s. Compute the minimum possible time (use units of hours, 3 significant figs) required to build the part, if 25 s are lost each layer to lower the height of the platform that holds the part. Neglect the time for setup and post-processing.

Answer:

1.443hrs

Explanation:

Please kindly check attachment for the detailed and step by step solution to the problem.

A small vehicle is powered by a pulsejet. The available net thrust is 6000 N and the traveling speed is 200 km/hr. The gases leave the engine with an average velocity (Ve) of 360 m/s Assume pressure equilibrium exists at the outlet plane and the fuel to air ratio is 0.06.

a. Compute the mass flow rate required
b. Calculate the inlet area (assume To is 16 °C and Po is one atmosphere)
C. Calculate the thrust power
d. Calculate the propulsive efficiency

A minor road intersects a major 4-lane divided road with a design speed of 55mph and a median width of 8 feet. The intersection is controlled with a stop sign on the minor road. If the design vehicle is a passenger car, determine the minimum sight distance required on the major road that will allow a stopped vehicle on the minor road to safely turn left if the approach grade on the minor road is 3%.

A shaft is loaded in bending and torsion such that Ma = 70 N ? m, Ta = 45 N ? m, Mm = 55 N ? m, and Tm = 35 N ? m. For the shaft, Su = 700 MPa and Sy = 560 MPa, and a fully corrected endurance limit of Se = 210 MPa is assumed. Let Kf = 2.2 and Kfs = 1.8. With a design factor of 2.0 determine the minimum acceptable diameter of the shaft using
a. ) DE-Gerber criterion.
b) DE-ASME Elliptic criterion.
c) DE-Soderberg criterion.
d) DE-Goodman criterion.

The arrival rate at a parking lot is 6 veh.min. Vehicles start arriving at 6:00PM and when the queue reaches 36 vehicles, service begins. If company policy is that total vehicle delay should be equal to 500 veh-min, what is the departure rate?

2.) For a 20‐mm‐diameter tube with either water or unused engine oil flowing through it, find: a.)The mean velocity, hydrodynamic entry length, and thermal entry length for each of the fluids with a temperature of 300 K if the mass flow rate is 0.01 kg/s. b.)The mass flow rate, hydrodynamic entry length, and thermal entry length for each fluid at 400 K and a mean velocity of 0.02 m/s.

A commercial enclosed gear drive consists of a 20o spur pinion having 16 teeth driving a 48-tooth gear. The pinion speed 350 rev/min, the face width 2 in, and the diametral pitch 6 teeth/in. The gears are grade 1 steel, through-hardened at 240 Brinell, made to No. 6 quality standards, uncrowned, and are to be accurately and rigidly mounted. Assume a pinion life of 108 cycles and a reliability of 0.90. Determine the AGMA bending and contact stresses and the corresponding factors of safety if 5 hp is to be transmitted.

A piston-cylinder assembly contains 2 lb of air at a temperature of 540 °R and a pressure of 1 atm. The air compressed to a state where the temperature is 840 °R and the pressure is 6 atm. During the compression, there is a heat transfer from the air to the surroundings equal to 20 Btu.
1. Using the ideal gas model for air, determine the work during the process in Btu.

Design a Mealy machine for a 20 cent candy dispensing machine which accepts nickel (n) , dime (d) and quarter(q) . It gives candy as well change in the form of nickels only. To help you, here are the some of the elements of the machine: States: 0, 5, 10 and 15 represent the amount of money already inserted in the machine. n, d and q representing coins inserted in the machine Output: c0 (candy and no change), c1 (one nickel as change), c2(two nickels as change ), c3 (three nickels as change), and c4 (four nickels as change)

A circular bar will be subjected to an axial force (P) of 2000 lbf. The bar will be made of material that has a strength (S) of 24 kpsi. After some calculation, the designer has selected a standard 1/2 in diameter (d) bar. The factor of safety (n) is ____. Round the answers to three significant digits.

A plate of an alloy steel has a plane-strain fracture toughness of 50 MPa√m. If it is known that the largest surface crack is 0.5 mm long and that the value of Y is 1.1, which of the following can be said about this plate when a tensile stress of 1000 MPa is applied?

A. It is not possible to determine whether or not the plate will fracture.
B. The plate will definitely not fracture
C. The plate will definitely fracture.

In your new role at Wayne Industries, you have been given the freedom to propose and develop your own project ideas. You have an idea for a frictionless piston-cylinder assembly. Your design requires the expansion of 0.25 m3 of air at 3.3 MPa and 280 oC to 180 kPa in a slow, isothermal process. In order to be approved for further development, you need to submit calculations for the values of the heat transferred in the process.

Consider airflow over a plate surface maintained at a temperature of 220°C. The temperature profile of the airflow is given as fluid ()()expsV TyTTTy     The airflow at 1 atm has a free stream velocity and temperature of 0.08 m/s and 20°C, respectively. Determine the heat flux on the plate surface and the convection heat transfer coefficient of the airflow.

Neglecting the presence of friction, air drag, and other inefficiencies, how much gasoline is consumed when a 1300 kg automobile accelerates from rest to 80 km/h. Assume the density and enthalpy of gasoline are 680 kg/m3 and 45 MJ/kg respectively. Express your answer in the units of mL. Show all work and use SI units for full credit. Box your final answer(s)

Determine the nature of the following cycle (reversible, irreversible, or impossible): a refrigeration cycle draws heat from a cold reservoir at 250 K and rejects 950 KJ to a hot reservoir at 300 K while receiving 70 kJ of work to operate. Draw a schematic of the cycle clearly indicating the hot and cold reservoir and the direction of heat and work transfers. (10 pts.)

Boron fibers (of total mass 5kg, rho B = 2.3g/cc, σy B = 55MPa) are uniaxially introduced into 8kg of an Al matrix (rho Al = 2.7g/cc, σy Al = 10MPa). There is no porosity before and after composite fabrication. Calculate the density of the composite, yield strengths parallel and perpendicular to fiber orientations.

Five hundred gallons of 89-octane gasoline is obtained by mixing 87-octane gasoline with 92-octane gasoline. (a) Write a system of equations in which one equation represents the total amount of final mixture required and the other represents the amounts of 87- and 92-octane gasoline in the final mixture. Let x and y represent the numbers of gallons of 87- and 92-octane gasoline, respectively. (b) Use a graphing utility to graph the two equations in part (a) in the same viewing window. As the amount of 87-octane gasoline increases, how does the amount of 92-octane gasoline change? (c) How much of each type of gasoline is required to obtain the 500 gallons of 89-octane gasoline?

The ice on the rear window of an automobile is defrosted by attaching a thin, transparent, film type heating element to its inner surface. By electrically heating this element, a uniform heat flux may be established at the inner surface. The inside air temperature and convection heat transfer coefficient are T,i = 25°C and hi = 25 W/(m2 -K), while the outside air temperature is T,o = -10°C. For 4-mm thick window glass, determine (a) the electric power required per unit window area to maintain an inner surface temperature of 15°C and (b) the thermal conductivity of the windshield.

The entire population of a given community is examined, and all who are judged to be free from bowel cancer are questioned extensively about their diets. These people then are followed for several years to see whether or not their eating habits will predict their risk of developing bowel cancer.

a. Cross-sectional study
b. Case-control study
c. Prospective cohort study
d. Historical prospective cohort study
e. Clinical trial
f. Community trial

Jasper and Gemma are going to play on a teeter totter. Gemma gets on first. When Jasper gets on, Gemma moves into the air, but she does not move to the top. Which statement could correctly explain the forces acting on the teeter totter? assume that Jasper and Gemma are the same distance from one another.

Specifically, the following methods must be implemented in the LinkedList class: (You should utilize listIterator() method already defined in the LinkedList class to obtain its LinkedListIterator object, and use the methods in the LinkedListIterator class to traverse from the first element to the last element of the linked list to define the following methods.)

The coupling is used to connect the two shafts together. Assuming that the shear stress in the bolts is uniform, determine the number of bolts necessary to make the maximum shear stress in the shaft equal to the shear stress in the bolts. Each bolt has a diameter dd. Express your answer in terms of some or all of the variables rrr, RRR, ddd, and TTT. nn

The function below takes a single string parameter called sentence. Your function should return True if the sentence contains at least one copy of each of the following vowels: a, e, i, o, and u. Otherwise, return False. The vowels can be either upper case or lower case.

student.py
Bef contains_all_values (sentence): 1 w

The air velocity in the duct of a heating system is to be measured by a Pitot-static probe inserted into the duct parallel to the flow. The differential height between the water columns connected to the two outlets of the probe is 0.126 m.Take the density of water to be 1000 kg/m3. The gas constant of air is R = 0.287 kPa-m3/kg-K.The air temperature and pressure in the duct are 352 K and 98 kPa, respectively.

The brakes on a vehicle work OK for a while, then the vehicle slows because the brakes self- applied. Technician A says that an overfilled master cylinder could be the cause. Technician B says that a blocked vent port (compensating port) could be the cause. Which technician is correct?


A. Technician A only

B. Technician B only

C. Both technician A and B

D/ Neither technician A nor B

Which of these actions can be taken to minimize number of victims or prevent injury? (check all that apply) A. Hire good lawyers to defend those responsible for the disater. B. Regular inspections of man-made structures by licensed inspectors. C. Alarm systems and plans for evacuation and shelter of all communities neighboring a site of a potential disaster. D. Include fail-safe mechanisms in the design of life-critical systems

Diesel-fueled generators are frequently used as backup electrical power sources for homes and hospitals. Consider a Diesel powered generator with an efficiency of 39 percent for an engine speed of idle to about 1,800 rpm (revolutions per minute). If Diesel fuel has a chemical formula of C12H23.
a. Determine the chemical reaction for 1 kmol of Diesel fuel burning with the stoichiometric amount of air.
b. For each kg of Diesel fuel burned, how much CO2 is generated, in kg?
c. Find the higher heating value (HHV) for C12H23 at 25°C, 1 atm.
d. Calculate the amount of Diesel fuel, in kg and in gallons, required to produce a power output of 18 kW to a home for a period of 8 h.
e. Comment on your results.

thermodynamics A nuclear power plant based on the Rankine cycle operates with a boiling-water reactor to develop net cycle power of 3 MW. Steam exits the reactor core at 100 bar, 620°C and expands through the turbine to the condenser pressure of 1 bar. Saturated liquid exits the condenser and is pumped to the reactor pressure of 100 bar. Isentropic efficiencies of the turbine and pump are 87% and 78%, respectively. Cooling water enters the condenser at 15°C with a mass flow rate of 114.79 kg/s. Determine: (a) the percent thermal efficiency. (b) the temperature of the cooling water exiting the condenser, in °C.

Utilizing the charge neutrality equation and the mass-action law derive an expression for the concentration of electrons and holes present inside a p-type compensated semiconductor material. How can the resulting expression be modified for practical cases where (????????AA − ????????DD) ≫ 2nn�

Ethanol is produced in a one-liter batch fermenter by Saccharomyces cerevisiae (yeast). To begin the batch process, glucose and ammonia are added to the reactor, which has been inoculated by the yeast. The reaction produces glycerol and cell mass, in addition to ethanol, carbon dioxide, and water according to the (unbalanced) reaction below. Note that that the mass ratio of glycerol produced to glucose consumed is 0.2556. Also note that the mass ratio of H.O produced to NH, consumed is 1.058 Glucose + Ammonia → Glycerol + Ethanol + Yeast Cell Mass + Carbon Dioxide + Water a CH (8) + b NH(g)}p CH 0 (1) + (CHO) +ỊCH K04 Nụ (8) + $ 0 g) + t H (1) Balance the equation and fill out the table below. (1 point cach, 6 total) a- 1 b = 115 g of NH, are added to the reactor. At the end of the batch, 640 g of ethanol has been produced. How much glucose was added (assume complete conversion of the limiting reactant). mlar B 16 points) BONUS QUESTION USING CHAPTER 4 CONCEPTS: The standard heat of combustion (AHC) for the yeast is-22.1 kJ/mol. In order to maintain a constant temperature, how much heat must be added or removed from the reactor? Both the sign and magnitude of your answer will be graded J 3 points)

You are provided the following information about a municipal wastewater treatment plant. This plant uses the traditional activated-sludge process.

Assume the microorganisms are 55 percent efficient at converting food to biomass, the organisms have a first-order death rate constant of 0.05/day, and the microbes reach half of their maximum growth rate when the BOD5 concentration is 10 mg/L. There are 150,000 people in the community (their wastewater production is 225 L/day-capita, 0.1 kg BOD5/capita-day). The effluent standard is BOD5 = 20 mg/L and TSS = 20 mg/L.

Suspended solids were measured as 4,300 mg/L in a wastewater sample obtained from the biological reactor, 15,000 mg/L in the secondary sludge, 200 mg/L in the plant influent, and 100 mg/L in the primary clarifier effluent. SRT is equal to 4 days.

(a) What is the design volume of the aeration basin (m3)?

(b) What is the plant