Is it possible to design products without any demand? Explain your answer with the likely consequences.

A vapor-compression heat pump with a heating capacity of 500 kJ/min is driven by a power cycle with a thermal efficiency of 30%. For the heat pump, Refrigerant 134a is compressed from saturated vapor at -10°C to the condenser pressure of 10 bar. The isentropic compressor efficiency is 80%. Liquid enters the expansion valve at 9.6 bar, 34°C. For the power cycle, 80% of the heat rejected is transferred to the heated space. (a) Determine the power input to the heat pump compressor, in kW (b) Evaluate the ratio of the total rate that heat is delivered to the heated space to the rate of heat input to the power cycle. Round answers to 3 significant digits.

One kg of Methance (CH4) is burned with 200% theoretical air. What is the air fuel ratio on a mass basis?

Consider a simple Brayton cycle using air as the working fluid with properties assumed constant and evaluated at room temperature (300 K). Conditions at the compressor inlet are T1 = 25°C and P1 = 200 kPa. The pressure ratio is 11 and maximum cycle temperature is 750°C. Answer the following (a) Compute the back?work ratio and cycle efficiency assuming both the turbine and compressor are isentropic (b) Compute the same quantities assuming only the turbine is isentropic while the compressor has an isentropic efficiency of 75% (c) Compute the same quantities assuming only the compressor is isentropic while the turbine has an isentropic efficiency of 75%

Please show all work, assume ideal gas and cold air assumptions and please write legible. Thanks

A 3-phase, 5 kVA, 208 V, four-pole, 60 Hz, Y-connected synchronous machine has negligible stator
winding resistance and a synchronous reactance of 8
per phase at rated terminal voltage. Themachine is operated as a generator and delivers rated kVA at 0.8 power factor lagging.

(a) Determine the excitation voltage,
(b) Find the power angle,
(c) Draw the phasor diagram,
(d) Find the stator current assuming that the field excitation current is now increased by 20 %
(without changing the prime mover power).

what is the enthalpy of formation for c4h8??????????????

A converging nozzle feeds an insulated square duct (L = 224 ft, W = H = 8.0 in, f = 0.02) with air flowing steadily at 7200 lbm/min. The inlet stagnation temperature and stagnation pressure are respectively equal to 116 deg F and 190 psia. Calculate the exit Mach number, exit pressure, exit stagnation pressure and exit stagnation temperature. Ans. 0.67, 70.2 psia, 94.9 psia, 116 deg F.

# Heat Transfer,

Why the ratio of (thermal resistance of conduction)/(thermal resistance of convection) must be less than .1 for a system to lumped.

Why is there this grinding teeth in automatic car system? Is it bad fuel, choice of oil, engine and gear meeting point, bad/faulty gear/transmission system

As speed increases in an engine with throttle body fuel injection, does the temperature of the air-fuel mixture at the intake manifold exit increase or decrease? Explain what parameters affect your answer.

A technician has learned all techniques and skills for material processing. But he has never learned material science. Now he wants to find a material that its weight is as light as aluminum and its tensile strength is as high as steel. So he comes to TTU for instruction. You, as an instructor, need to explain to him what material he can select, and what procedure/s he should undertake to approach the goal with minimal explanation (as brief as possible) on the reason/mechanism related to your suggestion.

2. Needs Assessment for Coastal Tool Rental

Kathleen Marsh is a recent community college graduate who plans to open an equipment and tool rental store in the next few months. The store will target do-it-yourselfers who need gardening and home improvement implements that may be too expensive to purchase for a limited project.

Although this is her first real venture as an entrepreneur, Kathleen worked in a tool rental shop during high school and college. Kathleen’s store, Coastal Tool Rental, will be in a new shopping center. Kathleen chose the location because a sizable community of family homes is nearby and because no major competition is located in the area, which is about 15 miles from the nearest large town. She has arranged to rent 2500 square feet of space in the shopping center. She has located a wholesaler who can provide her with a start-up inventory of common garden and home improvement implements. The wholesaler can also serve as a supplier for new and replacement tools, equipment, and consumables.

Kathleen majored in small business management, but she also took a number of computer- related courses as electives—including some classes on programming and on using word processing, spreadsheet, and database applications. Kathleen plans to purchase a desktop computer for use in her small business venture, but her start-up money and time are limited.

Kathleen is considering the following four options to keep track of equipment rentals:

1. A manual system of file cards for each piece of equipment and each customer

2. A computer-based system she would build using a spreadsheet or database application

3. A computer-based option she would program herself

4. An off-the-shelf software package designed for equipment renta

She has asked for your help to determine the feasibility of each of these options. Complete the following:

# First, prepare a list of interview questions for Kathleen that would help you make a recommendation to her.

# After you have a list of potential questions to ask in an interview, compare your questions with those of three classmates or coworkers. Work with your group to create one merged list of questions for Kathleen. Organize the questions under several main categories.

# When you have completed the list of interview questions, your instructor will provide you with Kathleen’s responses to several questions from an interview with her. Based on her responses, complete the following:

Briefly describe the pros and cons of the four options Kathleen is considering.

Based on what you know of Kathleen’s situation, which of the four options would you recommend to her? Explain your reasoning.

In order to implement one of these options, Coastal Tools Rental would need data on each rental item and each customer. List the fields you think Coastal would need to include in either a record for each rental tool or a record for each customer.