The United States Naval Reserve (Women's Reserve), better known as the WAVES (for Women Accepted for Volunteer Emergency Service), was the women's branch of the United States Naval Reserve during World War II. It was established on July 21, 1942 by the U.S. Congress and signed into law by President Franklin D. Roosevelt on July 30. This authorized the U.S. Navy to accept women into the Naval Reserve as commissioned officers and at the enlisted level, effective for the duration of the war plus six months. The purpose of the law was to release officers and men for sea duty and replace them with women in shore establishments. Mildred H. McAfee, on leave as president of Wellesley College, became the first director of the WAVES. She was commissioned a lieutenant commander on August 3, 1942, and later promoted to commander and then to captain.
The notion of women serving in the Navy was not widely supported in the Congress or by the Navy, even though some of the lawmakers and naval personnel did support the need for uniformed women during World War II. Public Law 689, allowing women to serve in the Navy, was due in large measure to the efforts of the Navy's Women's Advisory Council, Margaret Chung, and Eleanor Roosevelt, the First Lady of the United States.
To be eligible for officer candidate school, women had to be aged 20 to 49 and possess a college degree or have two years of college and two years of equivalent professional or business experience. Volunteers at the enlisted level had to be aged 20 to 35 and possess a high school or a business diploma, or have equivalent experience. The WAVES were primarily white, but 72 African-American women eventually served. The Navy's training of most WAVE officer candidates took place at Smith College, Northampton, Massachusetts. Specialized training for officers was conducted on several college campuses and naval facilities. Most enlisted members received recruit training at Hunter College, in the Bronx, New York City. After recruit training, some women attended specialized training courses on college campuses and at naval facilities.
The WAVES served at 900 stations in the United States. The territory of Hawaii was the only overseas station where their staff was assigned. Many female officers entered fields previously held by men, such as medicine and engineering. Enlisted women served in jobs from clerical to parachute riggers. Many women experienced workplace hostility from their male counterparts. The Navy's lack of clear-cut policies, early on, was the source of many of the difficulties. The WAVES' peak strength was 86,291 members. Upon demobilization of the officer and enlisted members, Secretary of the Navy James Forrestal, Fleet Admiral Ernest King, and Fleet Admiral Chester Nimitz all commended the WAVES for their contributions to the war effort.
I am getting confused by this question. Nevertheless, I tried answering this question.
When I see the word pulse, it brings to my mind a pulse travelling in a rope as shown in diagram below and I cannot relate dispersion to the rope medium in which pulse is travelling. What I do know is that...
Using the equations mentioned under this question, I came up with following analysis and directions of velocities on either side of ##x_1##. Also, I'm not sure if there is an easier qualitative way to know the velocity directions rather than do a detailed Calculus based analysis?
I know that standing waves form in an open organ pipe. Since, standing waves can only form from superposition of original wave and reflected wave, so there must be a reflected wave in an open organ pipe. But I fail to understand how sound wave can reflect at the open end of organ pipe.
The second diagram is my attempt at the solution, in which the dotted part is the pulse in the rope a very small interval of time after ##t=0##.
Point A should be at rest since we know wave is moving towards right and point A on the rope becomes a part of initial horizontal part of the string a...
In general, it seems that higher frequencies of a wave dissipate more than lower frequencies.
For sound waves, it explains why you can hear lower pitches from farther away. For a vibrating string or plate, the higher frequencies also dissipate first, with the fundamental fading last. For water...
Can someone give me a better intuition of bandwidth.
The way I see it, is that the bandwidth is the range of frequencies which a signal/wave is allowed to have. This doesnt feel complete though.
For example, how can I explain that TDMA, FDMA and CDMA are similar in this sense. As far as I know...
I understand how waves undergo superposition. However, for a standing wave, the reflected wave is a mirror opposite of the incoming wave. By the superposition principle, won’t the 2 waves add up to 0, at all points?
Using this stimulation: https://phet.colorado.edu/sims/html/wave-on-a-string/latest/wave-on-a-string_en.html
It looks like frequency is decreasing as I increase tension but online it says frequency increases as tension does. Also, Im unsure about what happens to the Period
My attempt:
p and T allows us to calculate ##Z=402 \frac{kg}{sm^2}## using ## Z=p*\sqrt(\frac{\gamma*M}{R*T})## . The sound intensity level at 10 meters allows us to calculate the intensity at 10 meters to be I=10``````^{-7} W/m^2 using ##50 = 10*log(I/I_0)##. Then, using the formula...
hi guys
i was trying to derive the general formula of two orthogonal waves
$$x^{2}-2xycos(δ)+y^{2} = A^{2} sin(δ)^{2}$$
where the two waves are given by :
$$x = Acos(ωt)$$
$$y = Acos(ωt+δ)$$
where ##δ## is the different in phase , i know it seems trivial but i am stuck on where should i begin...
Standing waves in a string fixed at one end is formed by incoming and reflected waves. If reflected waves are 180° out of phase with incoming wave, how could they combine to give an oscillating wave? Shouldn't it be completely destructive interference all the time across the whole length of string?
While studying the fundamentals of sound waves in organ pipe, I noted that the fact about phase of reflected waves is contradicting while referring multiple sources
This book of mine describes the reflection from a rigid surface/closed end to be in phase
Whereas this one describes the...
$$\int_{-\infty}^{\infty} \frac{e^{-i \alpha x}}{(x-a)^2+b^2}dx=(\pi/b) e^{-i \alpha a}e^{-b |a|}$$
So....this problem is important in wave propagation physics, I'm reading a book about it and it caught me by surprise.
The generalized complex integral would be
$$\int_{C} \frac{e^{-i \alpha...
for example the blue light wave have frequency of about 450Thz and the yellow wave have frequency of about 508thz (I found this data in the internet) , so if this two wave would get closer to each other we would observe them as green wave which have frequency of 526Thz .
so my question is...
I need to find the differential equations for each mass. ##y_1## is the equilibrium position, and ##y_2## is the second equilibrium position for each mass.
I was thinking consider the next sistem:
\begin{eqnarray}
k\Delta y-mg&=&m\frac{d^2 y_2}{dt^2}
\\ -2k\Delta y_1 -k\Delta y_2 -2mg...
I've marked the right answers.
They mainly indicate at power carried by the particles being zero, and here is my doubt- why should it be zero? Shouldn't it have some definite value?
I do understand that the kinetic energy is max at the y=0 and potential energy is max at y=A, but I don't know...
Hello everyone, in one of my projects I am dealing with the following problem:
We have a tank filled of water. If we assumed that a focused ultrasond beam hit the water perpendicularly to the surface. How
can I calculate the displacement of the water surface? In particular, I am interested in...
Q.1. The length of a stretched string fixed at both ends has a length of l=10 cm, mass per unit length ρ= 0.01 gm/cm. If the tension ' T ' is produced by hanging a 11 kg weight at both ends of the string, then calculate,
a) The wavelength of the first two harmonics,
b) The speed of the wave...
I've got the answer for (a). It's k = 0.78 N/m.
I'm having problems with (b). I know that the equation of displacement in this case should either be :
x(t) = Asin(ωt + φ)
or
x(t) = Acos(ωt - φ)
where A = amplitude
From what I understand, both the equation above should give the same result...
The values calculated was nowhere near the theoretical values, though I guessed they won't be as the results recorded was incredibly inaccurate. My teacher acknowledged the fact the final values won't be close to the theoretical ones but also said that my formula was wrong, that it works to find...
Since the membrane doesn't break, the wave is continuous at ##x=0## such that
##\psi_{-}(0,y,t) = \psi_{+}(0,y,t)##
##A e^{i(k \cos(\theta)x + k \sin(\theta)y - \omega t)} = A e^{i(k' \sin(\theta ') y- \omega t)}##
Which is only true when ## k' \sin(\theta ') = k \sin(\theta) ##.
From the...
I explained that Huygens principle states that each point on the wave front act as a point source which produces spherical waves which produce the interference pattern.
Now his question is that where are these points and wouldn't there be infinite number of points on each wave front creating...
I am uncertain if this belongs in the differential geometry thread because I don't know what area of mathematics my question belongs in to begin with, but of the math threads on physics forums, this one seems like the most likely to be relevant.
I recently watched a video by PBS infinite series...
Let's try inputting a solution of the following form into the two-dimensional wave equation: $$ \psi(x, y, t) = X(x)Y(y)T(t) $$
Solving using the method of separation of variables yields
$$ \frac {v^2} {X(x)} \frac {\partial^2 X(x)} {\partial x^2} + \frac {v^2} {Y(y)} \frac {\partial^2 Y(y)}...
I have encountered the following definition of interference:
Interference is a wave phenomenon in which two or more waves from coherent sources meet and superpose to form a resultant wave such that the amplitude of the resultant wave at any point is the vector sum of the amplitudes of the...
Steps that I've taken:
First, compute the derivative of the psi-function with respect to time and then take the square of the result
Second, input the result into the KE integration formula.
All that is left is to find the integrand, however this is where calculations became really "messy". It...
Can someone provide me intuitive visualization of how E or H field can be longitudinal in a waveguide (TM/TE)? TEM is easy to visualize, but how EM wave can behave like sound in a waveguide (constant phase and amplitude plane in the same direction)?
[Moderator: large bold font removed. In the...
I was in an argument about a jet engine and I was arguing that since there is a cutoff in terminology what would kill someone approaching a engine is not technically sound, but a shock wave, (I'm probably wrong about this, but that's not the question). That got me wondering how waves can catch...
I want to simulate 2D TM scattered fields (microwave range) for austria profile. Austria profile has 2 circles beside each other of certain dielectric and one ring below the circles. So basically I have three dielectric objects in the domain of interest and also positions of Tx and Rx are known...
I cannot find the correct answer anywhere online and the answer I keep getting is 5.4 (incorrect)
Please show me the process to get to the answer! Thank you
First I worked out the dispersion relations, which is pretty easy:
##M \ddot x_j = K x_{j-1} + K x_{j+1} - 2K x_j -mg \frac {x_j} {l} ## (All t-derivatives)
We know ##x_j## will be in the form ##Ae^{ijka}e^{-i\omega t}##
so the above becomes:
## -\omega^2M = K (e^{-ika}+e^{ika}-2)-\frac {g}...
I am a high school teacher and we were discussing waves and electricity in class today. One of my students asked me if electricity is a longitudinal wave or not and I had no idea how to answer.
So, I realize that electric fields are what drive electrons to move through conducting wires, but...
If I am given the width of the slit (b), wavelength of the light (λ), and the distance of the slit from the screen (D), how can I find the width of the central maximum (d)? My book says d/2=Dλ/b, but with no explanation and I don't understand why. Where does this formula come from?
Thank you...
We know that the charge on capacitors as a function of time takes the general form of:
##Q(x,t)=qe^{ijka}e^{-i\omega t}##
The voltage at each capacitor:
##V_j = \frac 1 C (Q_j-Q_{i+1})##
From KVL we have differential equation of t-derivatives:
##LQ'' + RQ' = V_{j-1} - V_{j}##
##LQ''+RQ'= \frac...
Again I am really confused, but I just put the travelling wave as:
##\psi(x,t) = Dcos(kx- \omega t)## for positive x
##\psi(x,t) = Dcos(kx+ \omega t)## for positive x
Then I simply differentiated and plugged in ##x=0##
##F(t) = - T D k sin(\omega t)##
and from this
## \langle P \rangle = T D^2...
My textbook explained that it would be hard to see the wavelength properties of a tennis ball because we would have to find a very tiny slit in which to pass the tennis ball through. The wavelength of the tennis ball can be calculated using debroglie formula: wavelength = h/p
I was wondering if...
Homework Statement
https://imgur.com/lGas78X
The solution to this question says 450Hz. However, when I attempted to compute the frequency using the wave equation and find the normal mode solutions, I get 750Hz
2. Homework Equations
I suspect that the solution could be wrong, is that the...
I've wondered this for a while but not known how to ask the question,
If light is a transverse wave, then what is it transverse to?
To elaborate, light travels in three-dimensions, radially. To me, this seems analogous to the sound wave, with pulses of pressure moving longitudinally to the...
Homework Statement
Why working formula for transverse and longitudinal arrangement in melde experiment different in Melde's experiment ?
Homework Equations
None. The corresponding equations are all derived from the same fact.
The Attempt at a Solution
So, I have understood that the tuning...
Hello. I started to work on pedrotti optics book (2nd edition) and i got confused about what is relativistic mass and why we use it rather than kinetic energy (1/2mc^2)?
Also in the beginning of these explanations there is one equation i barely understand nothing out of it. Could you please...
Homework Statement
The system is shown in the image. In the beaded string shown in Figure 1, the interval between neighboring beads is a, and the distance from the end beads to the wall is a/2. All the beads have mass m and are constrained to move only vertically in the plane of the paper...
Homework Statement
In the Fizeau's Experiment to determine the speed of light, let the gear have N teeth, the frequency of the rotating gear being f, the distance travelled by the light beam/ray L (distance b/w the gear and the mirror) and let there be n eclipses(blocking of the light beam)...
Homework Statement
How would you describe the motion of a string at two adjacent antinodes?
Homework Equations
N/A
The Attempt at a Solution
So would the antinodes not be moving since it's a standing wave? Or would they be moving in phase because they are propagating together?
Hi,
a simple question related to the gravitational wave detection.
The net effect of gravitational wave is basically the stretching of the space including all the measurements tools (meter sticks just to illustrate the concept) that could be used to detect it. I am aware of laser...