A Carnot cycle is executed in a closed system and uses 0.0025 kg of air as the working fluid. The cycle efficiency is 60 percent, and the lowest temperature in the cycle is 300 K. The pressure at the beginning of the isentropic expansion is 700 kPa, and at the end of the isentropic compression it is 1 MPa. Determine the network output per cycle.
> Consider two identical fans, one at sea level and the other on top of a high mountain, running at identical speeds. How would you compare (a) the volume flow rates and (b) the mass flow rates of these two fans?
> A small-diameter tube is inserted into a liquid whose contact angle is 110°. Will the level of liquid in the tube be higher or lower than the level of the rest of the liquid? Explain.
> What is the difference between air-standard assumptions and the cold-air-standard assumptions?
> What is the capillary effect? What is its cause? How is it affected by the contact angle?
> Repeat Prob. 9–18 using helium as the working fluid. Data from Prob. 9-18: An air-standard Carnot cycle is executed in a closed system between the temperature limits of 350 and 1200 K. The pressures before and after the isothermal compression are 150 an
> What is surface tension? What is its cause? Why is the surface tension also called surface energy?
> Reconsider Prob. 9–184. Using appropriate software, investigate the effect of evaporator pressure on the COP and the power input. Let the evaporator pressure vary from 120 to 380 kPa. Plot the COP and the power input as functions of evaporator pressure,
> A rotating viscometer consists of two concentric cylinders—a stationary inner cylinder of radius Ri and an outer cylinder of inside radius Ro rotating at angular velocity (rotation rate) ωo. In the tiny gap between the two cy
> A large refrigeration plant is to be maintained at −15°C, and it requires refrigeration at a rate of 100 kW. The condenser of the plant is to be cooled by liquid water, which experiences a temperature rise of 8°C as it flows over the coils of the condens
> A frustum-shaped body is rotating at a constant angular speed of 200 rad/s in a container filled with SAE 10W oil at 20°C (μ = 0.100 Pa⋅s), as shown in Fig. P10–30. If the thickness of the oil
> A heat pump that operates on the ideal vapor compression cycle with refrigerant-134a is used to heat a house. The mass flow rate of the refrigerant is 0.25 kg/s. The condenser and evaporator pressures are 1400 and 320 kPa, respectively. Show the cycle on
> Someone claims that the absolute pressure in a liquid of constant density doubles when the depth is doubled. Do you agree? Explain.
> Consider the flow of air over the wings of an aircraft. Is this flow internal or external? How about the flow of gases through a jet engine?
> Consider an ice-producing plant that operates on the ideal vapor-compression refrigeration cycle and uses refrigerant 134a as the working fluid. The refrigeration cycle operating conditions require an evaporator pressure of 140 kPa and the condenser pres
> Consider a steady-flow Carnot refrigeration cycle that uses refrigerant-134a as the working fluid. The maximum and minimum temperatures in the cycle are 30 and −20°C, respectively. The quality of the refrigerant is 0.15 at the beginning of the heat absor
> Repeat Prob. 10–28 for umax = 6 m/s. Data from Prob. 10-28: In regions far from the entrance, fluid flow through a circular pipe is one dimensional, and the velocity profile for laminar flow is given by u(r) = umax(1 −
> Rooms with floor areas of up to 15 m2 are cooled adequately by window air conditioners whose cooling capacity is 5000 Btu/h. Assuming the COP of the air conditioner to be 3.5, determine the rate of heat gain of the room, in Btu/h, when the air conditione
> In regions far from the entrance, fluid flow through a circular pipe is one dimensional, and the velocity profile for laminar flow is given by u(r) = umax(1 − r 2/R2), where R is the radius of the pipe, r is the radial distance from the
> An air-standard Carnot cycle is executed in a closed system between the temperature limits of 350 and 1200 K. The pressures before and after the isothermal compression are 150 and 300 kPa, respectively. If the net work output per cycle is 0.5 kJ, determi
> For flow over a plate, the variation of velocity with vertical distance y from the plate is given as u(y) = ay − by2 where a and b are constants. Obtain a relation for the wall shear stress in terms of a, b, and μ.
> A steam power plant operates on an ideal Rankine cycle with two stages of reheat and has a net power output of 75 MW. Steam enters all three stages of the turbine at 550°C. The maximum pressure in the cycle is 10 MPa, and the minimum pressure is 30 kPa.
> A 50-cm × 30-cm × 20-cm block weighing 150 N is to be moved at a constant velocity of 1.10 m/s on an inclined surface with a friction coefficient of 0.27. (a) Determine the force F that needs to be applied in the horizontal dire
> A health magazine reported that physicians measured 100 adults’ blood pressure using two different arm positions: parallel to the body (along the side) and perpendicular to the body (straight out). Readings in the parallel position were up to 10 percent
> Consider a steam power plant operating on the ideal Rankine cycle with reheat between the pressure limits of 30 MPa and 10 kPa with a maximum cycle temperature of 700°C and a moisture content of 5 percent at the turbine exit. For a reheat temperature of
> Reconsider Prob. 10–24. Using appropriate software, investigate the effect of oil film thickness on the torque transmitted. Let the film thickness vary from 0.1 mm to 10 mm. Plot your results, and state your conclusions. Data from Prob
> Steam enters the turbine of a steam power plant that operates on a simple ideal Rankine cycle at a pressure of 6 MPa, and it leaves as a saturated vapor at 7.5 kPa. Heat is transferred to the steam in the boiler at a rate of 40,000 kJ/s. Steam is cooled
> The clutch system shown in Fig. P10–24 is used to transmit torque through a 2-mm-thick oil film with μ = 0.38 N⋅s/m2 between two identical 30-cm-diameter disks. When the driving shaft rotates at a speed o
> Feedwater at 4000 kPa is heated at a rate of 6 kg/s from 200°C to 245°C in a closed feedwater heater of a regenerative Rankine cycle. Bleed steam enters this unit at 3000 kPa with a quality of 90 percent and leaves as a saturated liquid. Calculate the ra
> Helium is used as the working fluid in a Brayton cycle with regeneration. The pressure ratio of the cycle is 8, the compressor inlet temperature is 300 K, and the turbine inlet temperature is 1800 K. The effectiveness of the regenerator is 75 percent. De
> A rotating viscometer consists of two concentric cylinders—an inner cylinder of radius Ri rotating at angular velocity (rotation rate) ωi, and a stationary outer cylinder of inside radius Ro. In the tiny gap between the two c
> Consider a simple ideal Brayton cycle operating between the temperature limits of 300 and 1250 K. Using constant specific heats at room temperature, determine the pressure ratio for which the compressor and the turbine exit temperatures of air are equal.
> A thin 30-cm × 30-cm flat plate is pulled at 3 m/s horizontally through a 3.6-mm-thick oil layer sandwiched between two plates, one stationary and the other moving at a constant velocity of 0.3 m/s, as shown in Fig. P10–22.
> An ideal dual cycle has a compression ratio of 14 and uses air as the working fluid. At the beginning of the compression process, air is at 14.7 psia and 120°F, and it occupies a volume of 98 in3. During the heat-addition process, 0.6 Btu of heat is tran
> Explain why some people experience nose bleeding and some others experience shortness of breath at high elevations.
> The viscosity of a fluid is to be measured by a viscometer constructed of two 75-cm-long concentric cylinders. The outer diameter of the inner cylinder is 15 cm, and the gap between the two cylinders is 1 mm. The inner cylinder is rotated at 300 rpm, and
> A typical hydrocarbon fuel produces 43,000 kJ/kg of heat when used in a spark-ignition engine. Determine the compression ratio required for an ideal Otto cycle to use 0.039 g of fuel to produce 1 kJ of work. Use constant specific heats at room temperatur
> Consider the flow of a fluid with viscosity μ through a circular pipe. The velocity profile in the pipe is given as u(r) = umax(1 − rn/Rn), where umax is the maximum flow velocity, which occurs at the centerline; r is the
> A four-cylinder, four-stroke, spark-ignition engine operates on the ideal Otto cycle with a compression ratio of 11 and a total displacement volume of 1.8 L. The air is at 90 kPa and 50°C at the beginning of the compression process. The heat input is 0.
> Define incompressible flow and incompressible fluid. Must the flow of a compressible fluid necessarily be treated as compressible?
> Repeat Prob. 9–169 using argon as the working fluid. Data from Prob. 9-169: Consider an engine operating on the ideal Diesel cycle with air as the working fluid. The volume of the cylinder is 1200 cm3 at the beginning of the compression process, 75 cm3
> The dynamic viscosity of carbon dioxide at 50°C and 200°C are 1.612 × 10–5 Pa·s and 2.276 ×10–5 Pa·s, respectively. Determine the constants a and b of the Sutherland correlation for carbon dioxide at atmospheric pressure. Then predict the viscosity of ca
> Repeat Prob. 9–16E using constant specific heats at room temperature. Data from Prob. 9-16: An air-standard cycle with variable specific heats is executed in a closed system and is composed of the following four processes: 1-2 v = constant heat addition
> The viscosity of a fluid is to be measured by a viscometer constructed of two 5-ft-long concentric cylinders. The inner diameter of the outer cylinder is 6 in, and the gap between the two cylinders is 0.035 in. The outer cylinder is rotated at 250 rpm, a
> Consider an engine operating on the ideal Diesel cycle with air as the working fluid. The volume of the cylinder is 1200 cm3 at the beginning of the compression process, 75 cm3 at the end, and 150 cm3 after the heat-addition process. Air is at 17°C and 1
> What is the difference between gage pressure and absolute pressure?
> A Diesel cycle has a compression ratio of 22 and begins its compression at 85 kPa and 15°C. The maximum cycle temperature is 1200°C. Utilizing air-standard assumptions, determine the thermal efficiency of this cycle using (a) constant specific heats at r
> Consider two identical small glass balls dropped into two identical containers, one filled with water and the other with oil. Which ball will reach the bottom of the container first? Why?
> An Otto cycle with a compression ratio of 8 begins its compression at 94 kPa and 10°C. The maximum cycle temperature is 900°C. Utilizing air standard assumptions, determine the thermal efficiency of this cycle using (a) constant specific heats at room te
> How does the kinematic viscosity of (a) liquids and (b) gases vary with temperature?
> What is viscosity? What is the cause of it in liquids and in gases? Do liquids or gases have higher dynamic viscosities?
> Repeat Prob. 9–164 using constant specific heats at room temperature. Data from Prob. 9-164: An air-standard cycle with variable specific heats is executed in a closed system with 0.003 kg of air, and it consists of the following three processes: 1-2 Is
> What is a Newtonian fluid? Is water a Newtonian fluid?
> An air-standard cycle with variable specific heats is executed in a closed system with 0.003 kg of air, and it consists of the following three processes: 1-2 Isentropic compression from 100 kPa and 27°C to 700 kPa 2-3 P = constant heat addition to initia
> In a piping system, the water temperature remains under 30°C. Determine the minimum pressure allowed in the system to avoid cavitation.
> Heated air is at 150°C. What is the temperature of this air in °F?
> What is the difference between pound-mass and pound-force?
> Why does a bicyclist pick up speed on a downhill road even when he is not pedaling? Does this violate the conservation of energy principle?
> The president of Circle H assigned you to perform a complete investigation to determine the causes of certain quality problems and to recommend appropriate corrective action. You have authority to talk to any other person within the company. The early st
> The Cincinnati Water Works (CWW) serves approximately 1 million customers.59 Its billing system allows customer service representatives (CSRs) to retrieve information from customer accounts quickly using almost any piece of data such as customer name, ad
> Legal Sea Foods operates several restaurants and fish markets in the Boston area and other East Coast locations. The company’s standards of excellence mandate that it serves only the freshest, highest quality seafood. It guarantees the quality by buying
> How can a manager effectively balance the three key components of a service system design?
> Refer to Example 5.1 and Figure 5.3: Example 5.1: Suppose that a hospital wants to design a process for administering medication to a patient. Clearly, the last subprocess is “patient receives medicine.” The input to
> List some of the common processes that your college or university has, and with which you interact. How might these processes be improved?
> Provide some examples of processes that are repeat able and measurable and some that are not.
> Identify some of the key processes associated with the following business activities for a typical company: sales and marketing, supply chain management, managing information technology, and managing human resources.
> The kaizen philosophy seeks to encourage suggestions, not to find excuses for failing to improve. Typical excuses are “If it’s not broken, don’t fix it,” “I’m too busy to work on it,” and “It’s not in the budget.” Think of at least five other excuses why
> A. Blanton Godfrey notes that many organizations are “wired for failure”; that is, their processes are not designed effectively or aligned with each other.58 He cites several examples. One is overscheduling at airports. During the 4:15 to 4:30 p.m. time
> Rosie’s Pizzeria is a privately held chain of neighborhood pizzerias with over 50 locations in the Midwest that offers full-service dine-in, carryout, and home delivery. Rosie’s competes against such national chains as Pizza Hut, Papa John’s, and other l
> Think of a job you have had. Apply the Hackman and Oldham model to evaluate how the job design impacted your motivation and satisfaction, as well as organizational effectiveness.
> When simple theories such as those of Maslow, Herzberg, and McGregor explain motivation, why does the search continue for more complex ones or for ones that integrate several different theories, such as Porter and Lawler’s theory? What implications do th
> What motivates you to study and perform in the classroom? How do motivation theories apply to you personally? Discuss how these theories might lead to new ways of teaching and learning.
> An engineering service firm that performs repair and maintenance of laboratory equipment asks its technicians to write weekly journal entries describing their work experiences. The company owner reviews them each week and provides feedback to the technic
> Explain how a focus on the following can lead to high levels of employee engagement. Provide specific examples of professions that support each of these. a. Employees’ jobs benefit their customers and society as a whole. b. Employees find personal meani
> What things might you observe in an organization that has high levels of workforce engagement? What might you observe in one that has low levels of engagement?
> How can a fraternity or student organization use the workforce-focused practices in Table 4.1 to improve the organization? If you are involved in such an organization, develop a strategic “workforce” plan that supports performance excellence.
> The training strategy that Xerox used is summarized as follows: a. The training is uniform—common tools and processes are taught across all of Xerox, to all employees, creating a “common language within Xerox” that fosters cohesive team functioning. b.
> Often, the preamble to one’s call to a company will be a recorded message that says something like “For quality purposes, this call may be recorded.” What do you think the real purpose of such an approach is? Is it to improve quality or to monitor poorly
> Many companies today seek the best available applicants and train them in quality principles. What implications does this practice have for designing college curricula and choosing elective courses in a given program?
> Ron Hagler, the vice president of sales for Selit Corp., had just received a report on the past five years of quarterly sales data for the regions under his authority (see sales data shown in the Excel file C02 Quarterly Sales Case Data on the Student Co
> Recently, new “employee performance software” has been developed to track individual output. For example, British Airways uses it to ensure that customer service reps’ time in the break room or on personal calls doesn’t count on the clock. The technology
> Jack Welch, former CEO of General Electric, stated his passion for making people GE’s core competency yet he used a system in which executives in the bottom 10 percent of a forced performance ranking were eliminated. What do you think of this approach? H
> Most colleges and universities use a course/ instructor evaluation system. If your school has one, how is it used? Does it support continuous improvement or is it used strictly for performance appraisal? How might the evaluation instrument or process be
> The late Peter Drucker, arguably one of the most respected and influential writers on management in the twentieth century, observed: Whatever his limitations and shortcomings—and he had many—no other American, not even Henry Ford (1863–1947), had anythin
> Discuss the controversy over performance appraisal. Do you agree with Deming’s approach, or do you take the more traditional viewpoint toward performance appraisal? Why?
> Students in early grades often receive many kinds of recognition: stickers, candy, and so on, for good work. As we discussed, similar forms of recognition are common in the workplace. Yet little daily recognition is given at the high school and college l
> Employees at the Container Store are said to be paid about twice the national average. The CEO feels that he is receiving three times the productivity of an average worker at only twice the cost. Do you think that this is true? What are the pros and cons
> Discuss the conditions under which team incentives, gainsharing, and “pay for increased skills” reward systems may work. When is it a poor idea to install such systems?
> Consider the statement, “How one is evaluated determines how one performs.” What does this notion mean for your classes? Would your performance change if grades were abolished (as Deming strongly advocated)?
> How should teams deal with “slackers”? How would you deal with them in the context of a student project team?
> Walker Auto Sales and Service (WASS) is a full-service dealership for a major domestic automobile brand. Essentially, WASS provides three main services: new car sales, used car sales, and repair and maintenance service. Because of the competitive nature
> How might a jazz quartet be viewed as a metaphor for a team in a business situation?
> How might the concept of empowerment be employed in a classroom?
> Cite some examples of empowerment or lack of empowerment from your own experiences.
> Describe some examples of job enlargement or job enrichment that you have either seen or personally encountered in a job.
> What is your reaction to Clifton Leaf ’s comments in the opening paragraph of the chapter? Do you feel these hold for most other organizations?
> Distinguish among consumers, external customers, and internal customers. Illustrate how these concepts apply to a Chipotle’s restaurant, a Walmart, or a similar franchise or chain store.
> Summarize the six quality perspectives described in this chapter.
> What practices do Motorola and Mid-American Transplant in the Quality Profiles use to help them achieve high quality?
> What factors have contributed to the increased awareness of quality in modern business?
> Describe some approaches that organizations use to conduct Baldrige self-assessments.
