Question 1
a) A cylindrical feedstock of length = 35.4 cm and diameter = 10 cm is subjected to turning using a high speed steel tool. For this tool, n and C values in the Taylor tool life equation are 0.125 and 70 m/min, respectively. The cost for hiring an operator and using the machine tool are $82 per hour. The tooling cost per edge of cutting is $5. Loading and unloading the part on to the machine takes about 4 min, and it takes about 2.5 minutes to change the tool. At a feed rate of 0.25 cm/rev, calculate:
(i) cutting speed for maximum production rate,
(ii) tool life [minutes], and
(iii) cost per unit and total cycle time of a produced part.
b) On a rectangular stock of aluminium alloy [tensile strength = 305 N/mm² and yield strength = 215 N/mm²] with dimensions of length = 320 mm and width = 30 mm, peripheral milling is performed on the top surface. The diameter of the carbide milling tool is 60 mm, with 8 teeth. The milling tool is centred along the workpiece width. At cutting speed of 80 m/min, chip load of 0.17 mm/tooth, and a depth of cut of 5 mm, calculate the following:
(i) the time to complete one machining one pass across the surface, and
(ii) the rate of maximum material removal during this cut.
Question 2
a) List and describe the five processes that cause wear at the interface of the tool and chip and the interface of tool and work in machining. What are the two major factors which enhance tool wear mechanisms? Explain in detail.
b) List and describe the three main processes that cause grinding wheel wear. Define Grinding Ratio and explain in detail, the relationship between grinding ratio, surface finish, and wheel speed using a plot.
Question 3
a) In an Electrochemical Machining process, the feedstock is made of an aluminium alloy (Ultimate Tensile Strength=572 MPa, Tensile Yield Strength=503 MPa). The desired time to machine a hole (?=10 mm) through a 20 mm-thick part is 2.1 min at a feed rate of 0.18 mm/s. What are:
(i) the efficiency of the process in %, and
(ii) the current requirement in amps to achieve this machining time target?
b) Describe in detail the process of circular sawing with the aid of a freehand sketch. What are the two major mechanisms by which circular sawing is achieved and what materials are commonly used as circular saws of each type?
In: Mechanical Engineering
What is included in the "background" section of a research paper?
In: Psychology
What is the reason for I.R.C. Section 306 Stock
In: Accounting
In: Anatomy and Physiology
To understand the concept of tension and the relationship between tension and force.
This problem introduces the concept of tension. The example is a rope, oriented vertically, that is being pulled from both ends. (Figure 1) LetFu and Fd (with u for up and d for down) represent the magnitude of the forces acting on the top and bottom of the rope, respectively. Assume that the rope is massless, so that its weight is negligible compared with the tension. (This is not a ridiculous approximation--modern rope materials such as Kevlar can carry tensions thousands of times greater than the weight of tens of meters of such rope.)
Consider the three sections of rope labeled a, b, and c in the figure.
At point 1, a downward force of magnitude Fad acts on section a.
At point 1, an upward force of magnitudeFbu acts on section b.
At point 1, the tension in the rope is T1.
At point 2, a downward force of magnitude Fbd acts on section b.
At point 2, an upward force of magnitudeFcu acts on section c.
At point 2, the tension in the rope is T2.
Assume, too, that the rope is at equilibrium.
What is the magnitude F_ad of the downward force on section a?
What is the magnitude F_bu of the upward force on section b? express in terms of T_1.
In: Physics
16.
In addition to cash contributions to charity, Dean decided to donate shares of stock and a portrait painted during the earlier part of the last century. Dean purchased the stock and portrait many years ago as investments. Dean reported the following recipients:
| Charity | Property | Cost | FMV | |||
| State University | Cash | $ | 16,000 | $ | 16,000 | |
| Red Cross | Cash | 15,000 | 15,000 | |||
| State History Museum | Painting | 5,100 | 86,000 | |||
| City Medical Center | Dell stock | 38,000 | 27,000 | |||
b. Assume that Dean’s AGI this year is $200,000. Determine Dean’s itemized deduction for his charitable contributions this year and any carryover.
Deduction:
Carryover:
In: Accounting
Describe the three basic tasks of healthcare economics. Explain each one with examples of tools and techniques used to evaluate it. Consider that you are a consultant with a firm that has been selected by your state government to evaluate the economic state of healthcare. How would you initiate and manage your evaluation?
In: Economics
Describe the three basic tasks of healthcare economics. Explain each one with examples of tools and techniques used to evaluate it. Consider that you are a consultant with a firm that has been selected by your state government to evaluate the economic state of healthcare. How would you initiate and manage your evaluation?
In: Economics
Q1 Take a typical worker, Jordan. Before the onset of COVID-19, Jordon earned $30 per hour(after taxation) in their job. Assume that Jordan has no other sources of income or savings. Write down the equation of Jordan’s consumption budget constraint (for a single working day). Using a model with consumption on the vertical axis and hours of free time on the horizontal axis, plot Jordan’s budget constraint. Label all relevant elements of this diagram and state the value of the horizontal and vertical intercepts.
Q2 Now, add an indifference curve to the model you developed in Q1 and label it IC1. This indifference curve should be at a utility maximising point and show Jordan’s corresponding choice of consumption and hours of free time. As you have not been given any information regarding Jordan’s preferences, state one assumption that you have made about Jordan’s utility maximising choice and one assumption that you have made about the slope of Jordan’s indifference curve.
Q3 The arrival of COVID-19 brought financial hardship for Jordan’s employer. As a result, Jordan has had their hourly wage cut by 20% (a common occurrence around the world a t the moment). Write down a new equation for Jordan’s consumption budget constraint (for a single working day). Using the same model developed in Q1-Q2, plot Jordan’s new budget constraint. Clearly state the value of the horizontal and vertical intercepts.
Q4 Now, add a second indifference curve to the model you developed in Q1-Q3 and label it IC2. This indifference curve should be at a new utility maximising point and show Jordan’s corresponding choice of consumption and hours of free time. State what has happened to Jordan’s choice of consumption and free time. What can be said about Jordan’s overall level of utility after the onset of COVID-19?
Q5 Using the model created in Q1-Q4, show the income effect, substitution effect and overall effect of Jordan’s wage decrease. Compare the relative size of the income and substitution effects shown on your model. What can be inferred about Jordan’s preferences for free time and consumption from this comparison? Q6 Explain the economic link between opportunity cost and a decrease in wages. How might this have impacted Jordan’s utility maximising choice?
In: Economics
explain why economic investment in capital represents a trade-off between present and future consumption in detail?
In: Economics