a) Construct a 99% confidence interval for the true proportion of all female students who were on a diet at the time of this study.
b) Explain what this interval means.
c) Is it reasonable to think that only 17% of college women are on a diet?
In: Statistics and Probability
1 Ideal Gas Law The ideal gas law is familiar to anyone who has taken a college chemistry course: P V = νRT. This problem will show you why the ideal gas law has this form. We can arrive at this expression just by using classical mechanics! Consider a box of volume V containing N particles, each having mass m, that are moving horizontally with average speed v. The particles bounce back and forth between the end walls of the container, which have area A. They are spread out uniformly in the box, so that there are n = N/V particles per cubic meter.
Single Collision — Consider a single particle bouncing off a wall of the container. In an elastic collision, how much momentum is transferred to the wall of the container? (The wall has a much greater mass than a particle.)
Multiple Collisions — If there are N collisions like the one you analyzed in the preceding question, how much momentum will be transferred to the wall? Time Interval — How many collisions will occur in time ∆t? Express your result N in terms of the average speed v, the particle density n, the area of the wall A, and the time interval ∆t. (Remember: At any given time, only half the particles will be moving toward the wall; the other half will be moving away.)
Average Force — What is the average force on the wall due to the N collisions of the previous question? (Recall Newton’s Second Law: F = ∆p/∆t.)
Average Pressure — What is the average pressure on the wall?
Kinetic Energy — Rewrite your result in terms of the average kinetic energy of the particles: E = 1/ 2mv^2 .
Ideal Gas Law? — Rearrange your result to resemble the ideal gas law. That is, derive an expression that relates P, V , N, and E.
Average Energy — What value of the average energy E would give the physicists’ version of the ideal gas law, P V = N kBT?
In: Physics
In matlab I have created the following function that calculates
the distance a projectile travels when shot from
a cannon given initial velocity and theta.
function [distance, xplot, yplot] = Cannon_lab8(V, theta)
g = -9.81; % gravity m/s^2
k = 0.35; % drag coefficient
Vx = V*cos(theta); %velovity in x-direction
Vy = V*sin(theta); %velovity in y-direction
dt = 0.01; % seconds, time step
x = 0;
y = 0;
xplot(1) = 0;
yplot(1) = 0;
i = 2;
while y >= 0
ax = -k*Vx;
ay = -k*Vy + g;
Vix = Vx;
Viy = Vy;
Vx = Vx + ax*dt;
Vy = Vy + ay*dt;
Vx_avg = (Vix +Vx)/2;
Vy_avg = (Viy +Vy)/2;
dy = Vy_avg * dt;
dx = Vx_avg * dt;
y = y + dy;
x = x +dx;
xplot(i) = x;
yplot(i) = y;
i = i + 1;
end
distance = x; % meters
scatter(xplot,yplot)
axis equal
I am now trying to determine the theta value needed to hit a target. The general aproach to solving for theta is by creating a new function that takes the guess value of theta, the initial velocity, and target distance, and solves for theta needed to hit the target. In this function the distance that the cannon misses the taret by can be calculated and this can be repeaditly calculated until the miss is within 2. so far I have:
function [theta_target] = aim_lab9(theta_guess, target,
V)
miss = Cannon_lab8(V, theta) - target;
dtheta = 0.1;
while abs(miss) > 2
miss = Cannon_lab8(V, theta_guess) - target;
theta_new = theta_guess + dtheta;
miss2 = Cannon_lab8(V,theta_new) - target;
end
I need help determining the theta_target. I would also like for the code to check and see if the target is within range.
thank you!
In: Computer Science
Read these instructions carefully, and then read the text “The
Highs and Lows of Vocational
Education” on the next page. Then write an essay of 350-400 words*
in response to this essay title:
You must support your ideas with:
- Evidence taken from the ‘The Highs and Lows of Vocational
Education” reading text (at
least one item, which must be referenced with an in-text
citation)
AND
- Other evidence regarding either Hong Kong OR China (which you may
have read and can
reference correctly, or which you have made up and should be
referenced with your family
name and the current year, e.g. (Fan, 2019). You are not required
to write a reference list.
Describe the advantages and disadvantages of studying vocational education, in either Hong
Kong or China, and in another country.
The Highs and Lows of Vocational Education [adapted]
by Matt Barnum (2017)
What’s one education topic that right wing, left wing, and all
politicians support? It is vocational
training - something they’ve all said America needs in order to
create a balance of practical as well
as academic school leavers. While President Trump praised Germany’s
approach to vocational
education recently, he actually plans to reduce funding for it,
but, at least in theory, there’s wide
support for helping more students learn career-specific
skills.
Yet new international research points to a significant downside of
such programs: Students may
benefit early in their careers, but are harmed later in life as the
economy changes and they lack the
less specific skills necessary to adapt. The study raises concerns
about the positive and negative
effects of expanding vocational training in the United States.
“Individuals with general education
initially face worse employment outcomes, but with improved
experience as they become older,
they have increased employment opportunities, relative to
individuals with vocational education,”
write four researchers in the study.
Many European and developing countries provide extensive vocational
training, including
apprenticeships with involvement from industry, the authors note.
That stands in contrast with the
U.S., which has reduced or eliminated separate vocational tracks in
most high schools. Looking at
11 European countries, the researchers compared students within the
same country who went on the
vocational track to similar students who went through a
general-education program. The result is
that although vocational students make higher salaries and are more
likely to be employed as young
adults, this advantage fades over time; by their late forties,
those who went through a general
education program have higher employment rates. Those findings were
confirmed with more
detailed data from Germany. “The advantages of vocational training
in smoothing entry into the
labor market have to be set against disadvantages later in life,”
the study concludes.
At age 10, Germany requires students to choose a vocational high
school, academic high school, or
what one article described as “something in between.” Students have
frequent opportunities to move
between these choices as they progress with their studies. However,
in the U.S., vocation-focused
courses are often just a small part of a student’s course load. As
of 2009, the average American
student took 3.6 vocational classes in high school.
The authors of the latest research say the findings don’t imply
that vocational education is
necessarily a bad idea, just that it is important to understand the
advantages and disadvantages of
each choice. The results also suggest that policymakers looking
only at the short-term impacts of
such programs may not be getting an accurate understanding of their
effects. One recent study of
Arkansas’s high-school vocational program, which requires students
to take six career-focused
classes in high school in order to graduate and allows them to
concentrate in specific areas, found
that participants had higher earnings and employment rates as young
adults. Longer-run impacts
were not examined, however.
In: Finance
In the circuit of Figure P32.48,
the battery emf is 80 V, the resistance R is 240 , and the
capacitance C is 0.500 µF. The switch S is closed for a long time,
and no voltage is measured across the capacitor. After the switch
is opened, the potential difference across the capacitor reaches a
maximum value of 150 V. What is the value of the inductance
L?
In: Physics
The following groups are stakeholders of a public company:I) shareholders; II) the government; III) suppliers; IV) employees; V) bondholders; VI) management Select one:
a. I, II, III, IV, V, and VI
b. I and II only c. I, II, III, and IV only
d. I, II, and III only
In: Accounting
Use the Gram-Schmidt process to construct an orthogonal basis of the subspace of V = C ∞[0, 1] spanned by f(x) = 1, g(x) = x, and h(x) = e x where V has the inner product defined by < f, g >= R 1 0 f(x)g(x)dx.
In: Advanced Math
A particle with mass m and energy E is moving in one-dimension from right to legt. It is incident on the step potential V(x)=0 for x<0 nd V(x)=V0 for x>0 where E>V0>0. Find the reflection coefficient R in terms of m,E and V0, and h-bar.
In: Physics
Use the postulates of the kinetic moleclar theory (KMT) to explain why boyle's law, charles's law, avogadro's law, and dalton's law of partial pressures hold true for ideal gases. Use the KMT to explain the P versus n (at constant V and T) relationship and the P versus T (at constant V and n) relationship.
In: Chemistry
In: Biology