A 20 kg block of iron and a 50 kg block of lead are sealed together in a tank with 5 kg of air. Initially the iron, lead, and air are at 200°C, 150°C, and 20°C, respectively. The air is initially at 100 kPa. After some time, the final system reaches thermal equilibrium and the air pressure inside the tank is 141 kPa. How much heat transfer occurred between the tank and the surrounding 20°C air? How much total entropy has been generated? There is air inside and outside of the tank.
In: Mechanical Engineering
Mark Each One True (T) or False (F)
33. Polymers have only covalent bonding and no other type of bonding.
34. Weight average molecular weight and number average molecular weight are the same.
35. Teflon is the same structure as polyethylene but with one out of every four H replaced by F.
36. Organic polymers have C-C bonding.
37. Thermoset plastics are easily melted to form recycled products.
38. Ceramics at room temperature can have both elastic and plastic deformation in tension if the stress is high enough.
39. The lowest density structural metal is Mg.
40. Ti is used in biomedical implants.
41. Wrought iron has less than 0.008 wt.% C and is very soft and easy to form.
42. Cast iron has high amounts of carbon (2-4.5 wt.%) are is relatively hard and brittle.
43. Stainless steels contain Cr to prevent corrosion.
44. The higher the hardenability, the more difficult it is for a steel to transform to martensite when quenched from an annealing temperature.
45. Ceramics can have mixed ionic-covalent bonding.
46. In general, polymers are more ductile than metals.
47. The fracture stress for most polymeric materials is lower than most metals.
48. Polyvinyl chloride (PVC) is made with only Cl and C atoms.
49. SiO2 based glasses have an amorphous structure.
In: Mechanical Engineering
A horizontal uninsulated steam pipe passes through a large room whose walls and ambient air are at 300 K. The pipe of 125-mm diameter has an emissivity of 0.85 and an outer surface temperature of 373 K. Calculate the rate of heat loss per unit length from the pipe.
Answer should be close to 384W/m
Please show all work neatly
In: Mechanical Engineering
product safety for engineers
Why can a manufacturer be held liable if an injury is due to person’s use of the manufacturer’s product in a way which was not intended?
In: Mechanical Engineering
Using the SSL values of T, p and ρ,calculate the standard atmosphere values at an altitude of 22km using the equations and graphs. How do these values compare to the values found from the tables?
In: Mechanical Engineering
THERMO-SYSTEM ANALYSIS AND DESIGN
2) Draw "Solar Tower" CSP plant with thermal energy storage.
In: Mechanical Engineering
Identify three recently formed alliances. For each alliance, identify whether the companies' other products are generally competitors or completmentary products. What are the goals of each alliance? What brought them together? Discuss whether you think a stragetic alliance is an effective way for these organizations to meet their goals.
In: Mechanical Engineering
Technical terms to research from Ch-6 and discuss the meaning/importance in 2-3 sentences per term and draw a sketch for elaboration (directly copying verbatim answers from thesaurus will carry NO points)
(3) Breaking strength; (5) Toughness of material; (6) Impact resistance (7) Bending strength;
(24 points)
Text Book- The Science and Engineering of Materials, Askeland et al. (seven edition
Home Work- # 6 for Chapter 6
In: Mechanical Engineering
7- List two most desired properties for following engineered components:
Blade for industrial scale on-shore wind turbine
Vertical mount of industrial scale off-shore wind turbine
Gear teeth used in wind turbine driver
Text Book- The Science and Engineering of Materials, Askeland et al. (seven edition
Home Work- # 6 for Chapter 6
please type your answe in the computer
In: Mechanical Engineering
In a structural FEA analysis, an analyst says that a dynamic problem must be handled differntly than a static problem. Explain.
In: Mechanical Engineering
Steam enters a horizontal 15-cm-diameter pipe as a saturated vapor at 5 bar with a velocity of 10 m/s and exits at 4.5 bar with a quality of 95%. Heat transfer from the pipe to the surroundings at 300K takes place at an average outer surface temperature of 400 K. For operation at steady state, determine
(a) the velocity at the exit, in m/s.
(b) the rate of heat transfer from the pipe, in kW.
(c) the rate of entropy production, in kW/K, for a control volume comprising only the pipe and its contents.
(d) the rate of entropy production, in kW/K, for an enlarged control volume that includes the pipe and enough of its immediate surroundings so that heat transfer from the control volume occurs at 300 K.
In: Mechanical Engineering
Question 14. Which of the following statements is NOT
true about the components of a vector?
Any vector can be resolved into rectangular
components
Any vector can be resolved into non-rectangular
components
Components are rectangular when a vector is resolved
along mutually perpendicular axes
Components are non-rectangular when a vector is
resolved along axes forming 45 degree
None of the above
Question 15. Which of the following methods is more
appropriate when adding more than two vector?
Parallelogram method (law)
Triangle method (rule)
Components method
Trigonometric method
All of the above
Question 16. Which of the following statements is the
definition of the moment arm d of a
force F about a point O?
The moment arm is the distance from the point O to the
tail of the force F
The moment arm is the distance from the point O to the
tip of the force F
The moment arm is the distance from the point O to the
mid-point of the force F
The moment arm is the perpendicular distance from the
point O to the line of action of force F
None of the above
Question 17. Which of the following statements is NOT
true about the moment M about point O,
of a force F acting at a moment arm
distance d?
The moment of a force is proportional to both the
magnitude of a force and the moment arm
The moment of a force is proportional to the magnitude
of a force but inversely proportional to the moment arm
A moment of a force is its ability to cause a body to
rotate
The moment of a force is also known as
torque
None of the above
Question 18. Which of the following statements is true
about the relationship between the moment M, about
point O, of a force F acting at a
moment arm distance d?
The moment M is the product of the
force F and the moment arm d
The moment M is the ratio of the
force F to the moment arm d
The moment M is the ratio of the
moment arm d to the force F
The moment M is the sum of the
force F and the moment arm d
None of the above
Question 19. Which of the following states the
Varignon’s theorem?
The forces of action and reaction between interactive
bodies always have the same magnitudes and opposite
direction
In two dimensional case, moments can be added
algebraically
The moment of a force about a point is the same as the
moment of its vertical component about the same point
The position, along the line of action, of the point
of application of a force acting on a rigid body, does not alter
the conditions of equilibrium or motion of the body
None of the above
Question 20. Which of the following statements
characterizes a set of two forces forming a couple?
The two forces are equal in magnitudes
The two forces are of opposite directions
The lines of action of two forces distinct and
parallel
A, B, and C
None of the above
In: Mechanical Engineering
A new asteroid is found with a circular sun-orbit 1.27 AU. A spacecraft is going to be sent to investigate it. Please find the relative angular position of the asteroid to the earth when the satellite is sent if the Hohman transfer is used. Where the earth will be when the spacecraft reaches the asteroid? AU = 1.496×108 km.
In: Mechanical Engineering
Imagine you are a pipeline company trying to sell a new project to a shipper of oil for a new refinery.
Pipeline Length: 266 miles (16,853,760 inches)
The refinery is scheduled to take 300,000 barrels per day of Bakken Crude at typical temperatures. Temperature: 60 degrees Fahrenheit. Flow rate = 33687.5 in3/s. Kinematic viscosity: 3.337 centistokes or 0.0051723603 in2/s. Specific Gravity = 0.7
Calculate Reynold's number.
Friction Factor: 0.0275.
Calculate Pressure Drop.
Pipeline flows entirely through class I locations except for 10 miles located in a class IV location. You have the option of bypassing the class IV location by running the pipeline an additional 50 miles.
Pipe Diameter: 12 inches X-42 Schedule 20
Calculate Maximum Pressure
The inlet pressure of pumping stations should not fall below 400 psi.
Set distance between pumping stations optimally.
Calculate horsepower requirements
In: Mechanical Engineering
In: Mechanical Engineering