In a slowly cooled hypereutectoid iron-carbon steel,
the pearlite colonies are normally separated from each
other by a more or less continuous boundary layer of
cementite. Explain how this microstructure develops. Use
simple sketches to illustrate your answer
In: Mechanical Engineering
Solve the following boundary value problem by Laplace Transform.
(If you solve with another
method you will NOT get credit. There is nothing wrong about the
conditions.)
d2y
dt2 + y = cos(2t); y0(0) = 0; y0(
2
) = ?1:
In: Math
Imagine an octagon(8 vertices) with all its diagonals. Is it possible to draw this without lifting your pen (and no backtracking). If we attach a triangle for each boundary edges of the Octagon, can you draw this without lifting your pen? Explain
In: Advanced Math
Let ?be the solid region bounded by the surfaces ?=10−?2−?2and ?=1. Let ?be the boundary of ?. If ?⃗=<?,?,?>, compute the total flux over ?in two ways:(a)Directly as a surface integral.Include a sketch of ?in your answer (b)As a triple integral using the Divergence Theorem
In: Advanced Math
Find the solution to the boundary value problem:
?^2?/??2−6??/??+5?=0, ?(0)=10,?(1)=6
Please show me all your work, I want to know where I went wrong. Thank you!
In: Advanced Math
Find the eigenfunctions for the following boundary value problem.
x2y?? ? 15xy? + (64 + ?)?y ?=? 0, y(e?1) ?=? 0, ?y(1) ?=? 0.
In the eigenfunction take the arbitrary constant (either c1 or c2) from the general solution to be 1
In: Advanced Math
Compare the maximum thickness of the boundary layer that develops due to uniform flow past a flat plate when the fluid is
(a) air, (b) water, (c) glycerol.
The plate length is 3 m and the approaching fluid velocity is 4 m/s.
In: Other
2. Let x be a real number, and consider the deleted neighborhood N∗(x;ε).
(a) Show that every element of N∗(x;ε) is an interior
point.
(b) Determine the boundary of N∗(x;ε) and prove your answer is
correct.
In: Advanced Math
1. A researcher conducted a survey on a university
campus for a sample of 64 seniors. The research reported that
seniors read an average of 3.12 books in the prior academic
semester, with a standard deviation of 2.15 books. Determine the
probability that the sample mean is:
a) above 3.45
b) between 3.38 and 3.58
c) below 2.94
2. Al Gore, the Democratic candidate for President of
the USA in the 2000 election, believes that the proportion of
voters who will vote for a Democrat candidate in the year 2004
presidential elections is 0.65. A sample of 500 voters is selected
at random.
a. Assume that Gore is correct and p = 0.65. What is
the sampling distribution of the sample proportion ? Explain.
b. Find the expected value and the standard deviation
of the sample proportion .
c. What is the probability that the number of voters in
the sample who will vote for a Democrat presidential candidate in
2004 will be between 340 and 350?
3. A random sample of 10 waitresses in Iowa City, Iowa
revealed the following hourly earnings (including tips):
$19 18 15 16 18 17 16 18 20 14
If the hourly earnings are normally distributed with a standard
deviation of $4.5, estimate with 95% confidence the mean hourly
earnings for all waitresses in Iowa City.
4. The number of cars sold annually by used car
salespeople is normally distributed with a standard deviation of
15. A random sample of 400 salespersons was taken and the mean
number of cars sold annually was found to be 75. Find the 95%
confidence interval estimate of the population mean. Interpret the
interval estimate.
5. Suppose that in a large city, the annual income of
real estate agents is normally distributed with a standard
deviation of $7,500. A random sample of 16 real estate agents
reveals that the mean annual income is $52,000. Determine the 99%
confidence interval estimate of mean annual income of all real
estate agents in the city.
6. A medical statistician wants to estimate the average
weight loss of people who are on a new diet plan. In a preliminary
study, he guesses that the standard deviation of the population of
weight losses is about 10 pounds. How large a sample should he take
to estimate the mean weight loss to within 2 pounds, with 90%
confidence?
In: Statistics and Probability
Explain what it means to be ethical as it relates to personal, academic, and professional growth.
In: Psychology