Q1) In a food processing facility, a spherical container of inner
radius r1 =41 cm, outer radius r2 = 43 cm, and thermal conductivity
k = 2 W/m · °C is used to store hot water and to keep it at 105°C
at all times. To accomplish this, the outer surface of the
container is wrapped with a 510-W electric strip heater and then
insulated. The temperature of the inner surface of the container is
observed to be nearly 100°C at all times. Assuming 80 percent of
the heat generated in the heater is transferred to container
a) Express the differential equation and the boundary conditions
for steady one-dimensional heat conduction through the
container,
b) Obtain a relation for the variation of temperature in the
container material by solving the differential equation.
c) Determine the temperature at the center plane of the
container
In: Mechanical Engineering
My device is a BOILER
Choose the working fluid (substance) for your model device
Choose the inlet substance conditions such as temperature, pressure, velocity, mass flow rate or volume flow rate, quality, etc
Choose the outlet substance conditions based on the available information, or design the outlet conditions based on your research.
DRAW the system you are analyzing, including the SYSTEM BOUNDARY,
Show ALL INTERACTIONS between the system and surroundings on your drawing
Write the Conservation of mass equation as it applies TO YOUR SYSTEM
Write the Conservation of Energy equation as it applies TO YOUR SYSTEM
List all the assumptions and idealizations for the process
Calculate the thermo efficiency of the device. Be sure clearly shows equations, calculation process, intermediate answers/results,and final results. Units are critically important in all calculations.
In: Mechanical Engineering
An article predicts that "spit," spam that is delivered via internet phone lines and cell phones, will be a growing problem as more people turn to web-based phone services. In a poll of 5500 cell phone users, 25% indicated that they had received commercial messages and ads on their cell phones. Is there sufficient evidence that the proportion of cell phone users who have received commercial messages or ads in 2004 was greater than the proportion of 0.13 reported for the previous year? (Use α = 0.05. Round your test statistic to two decimal places and your P-value to four decimal places.)
In: Statistics and Probability
Calculate percentages for the following table. A prior Gamma analysis has indicated that the relationship is significant (p-value <0.05). Use these percentages to assess the strength (using the maximum difference method) and direction of this relationship.
|
FAMILY INCOME AND HAPPINESS (2004 GSS DATA) |
||||
|
Happiness |
||||
|
Family Income |
Not too happy |
Pretty happy |
Very Happy |
Total |
|
Below Average |
16 |
36 |
15 |
67 |
|
Average |
11 |
36 |
21 |
68 |
|
Above Average |
2 |
12 |
8 |
22 |
|
Total |
29 |
84 |
44 |
157 |
Write a bullet points describing the relationship between these two variables
In: Statistics and Probability
Q 2 - “Inflation is as violent as a mugger, as frightening as an armed robber and as deadly as a hit man.” Ronald Reagan (1911-2004)
a. There are two types of inflation. How are these different types of inflation reflected in the aggregate demand and aggregate supply (AD-AS) model? Use diagrams to illustrate your answer.
b. Governments may adopt fiscal policy to control one of these types of inflation. What type of fiscal policy can be adopted? Explain how this fiscal policy works. How would the ‘ratchet effect’ affect the effectiveness of this fiscal policy?
c. On a separate diagram, clearly illustrate your answer in (b).
In: Economics
A home theater in a box is the easiest and cheapest way to provide surround sound for a home entertainment center. A sample of prices is shown here (Consumer Reports Buying Guide, 2004). The prices are for models with a DVD player and for models with a DVD player.
In: Statistics and Probability
Complex finance problems using Excel.
Compute the semi-annual coupon payment, the accrued interest, the invoice price of the bond, and the Yield to Maturity (YTM) of your bond.
In: Finance
1. Describe the graph of the function without drawing the graph. Use the terms increasing, decreasing, concave up, concave down, vertical intercept, and horizontal asymptote, as appropriate.
f(t) = 0.75(3)t − 2
.the vertical intercept is (t, f(t)) =
.The function is increasing or decreasing and concave up or concave down?
2. Model the data with an exponential function, if appropriate. If an exponential function model is not appropriate for the situation, explain why. Do not use regression for this exercise.
Between 1960 and 2004, insurance company expenditures for health care increased at an ever-increasing rate. In 1960, $6 billion was spent on health care. In 2004, $659 billion was spent on health care.†
Is the exponential function model appropriate? If not, explain why.
. Yes, the exponential function model is appropriate.
. No, the exponential function model is not appropriate because there is a constant rate of change, meaning it is linear.
. No, the exponential function model is not appropriate because the growth rate is less than 1.
. No, the exponential function model is not appropriate because the change factor is less than 1.
Give the exponential model, if appropriate. (If not appropriate, enter DNE. Let H(t) be health care expenditures by insurance companies in billions of dollars, t years after 1960. Round the change factor to two decimal places.)
H(t) = ________ billion dollars.
3. State the two integer values between which the expression falls.
log2(40)
Smaller value:-
Larger value:-
Use the change of base formula to evaluate the expression exactly. (Round your answer to three decimal places.):- __________
In: Statistics and Probability
Create an "IPCC-like" stabilization scenario using the following simplified information. Starting in the year 2004, the concentration of CO2 in the atmosphere is 378 ppm, the global emissions of CO2 are 7.4 Gt carbon per year, the total carbon in the atmosphere is 767 Gt, and emissions are growing by 4% per year, for example, in 2005 emissions reach 7.7 Gt, 8.0 Gt in 2006, and so on. Note that concentration is given in terms of CO2, but emissions and atmospheric mass are given in Gt carbon. The oceans absorb 3 Gt net (absorbed minus emitted) each year for the indefinite future. The change or decline of emissions is influenced by "global CO2 policy" as follows: in year 2005, the emissions rate declines by 0.1 percentage points to 3.9%, and after that and up to the point that concentration stabilizes, the change is 0.1% multiplied by the ratio of the previous year's total emissions divided by 7.4 Gt, that is

After concentration stabilizes, emissions are 3 Gt year, so that emissions are exactly balanced by ocean absorption. To illustrate, Chg%2004 = 4% and Chg%2005 = 3.9%, and so on. Also, concentration can be calculated as 378 ppm X (total carbon in atmosphere/767 Gt).
(a) What is the maximum value of concentration reached?
(b) In what year is this value reached?
(c) What is the amount of CO2 emitted that year?
(d) Plot CO2 concentration and emissions per year on two separate graphs.
(e) The scenario in this problem is a simplification of how a carbon stabilization program might actually unfold in the future. Identify two ways in which the scenario is simplistic.
In: Accounting
|
Over the last 20 years, the number of students who hold a job while attending university fulltime has increased. Work responsibilities may ‘compete’ for time and energy with course responsibilities, and consequently, may affect student academic success. An educational researcher is interested in determining whether student employment influences academic success. The research has obtained a relevant sample of university students, and has determined the following information for each student:
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In our lecture on Planning Ahead: Sampling variability, you were introduced to a set of five (5) questions that can be used to help decide upon a relevant statistical inference procedure.
my answer to a is:
In: Statistics and Probability