Homework Statement
Low-mass stars like the Sun obey the core mass-luminosity relationship as they burn H in a shell and climb the RBG (Red Giant Branch). What is the energy released per unit mass when fusing hydrogen into helium?
Homework Equations
The core mass-luminosity relationship:
$$...
I was asked by a friend to explain why the frequency, ##f## and period, ##T## of a wave. The initial explanation I gave to them was as follows:
Heuristically, the period of a wave is defined as ##T=\frac{\text{number of units time}}{\text{cycle}}##, and its frequency as ##f=\frac{\text{number...
The first day of physics 211 (calculus based) at my school, our teacher started us out with dimensional analysis and it's importance. We started with the plank length which is in meters and while he didn't specify why, we used the plank constant ,gravitational constant, and the speed of light to...
http://clinicalgate.com/cardiac-cycle-control-and-synchronicity/ https://www.google.com.ua/search?q=LEFT+VENTRICULAR+VOLUME+AND+INTRAVENTRICULAR+PRESSURE&espv=2&biw=1067&bih=539&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiVsse425jPAhWoQJoKHW8SB5cQ_AUIBigB#imgrc=oRMLKAV09Kxa4M%3A can someone please...
So my question is, is there a relationship between the density of a medium you are traveling through and the maximum speed achieved for an object of constant mass and shape traveling with constant thrust in both mediums?
for example if i knew that an object traveled 8 times faster in 1 medium...
Hi,
I wonder which steps of my following deduce are wrong
dU=-dW
dU=mg dh
dW=Fdx
thus, mgdh=-Fdx (dx=dh)
then, F=-mg which is a constant in most of situation
However, F does change in some situation.
I am confused about this.
Homework Statement
I'm doing an investigation for my physics class, where we were told to investigate the relationship between current flowing through and the efficiency of an immersion heater. My hypothesis was that as current increased, the efficiency would decrease due to the relationship...
Hey guys!
So the below question might sound like a homework question but in reality it is an oversimplified explanation of what I'm trying to measure
Let's say we have a perfect machine that pushes out 600CFM into a box. On the other end of the box is another small machine that only consumes...
I read in a book that the pressure caused by a wind blowing against a structure increases as the square of the wind velocity. I cannnot logically understand how that makes sense, and I can't think of any equation to support it. Can somebody please shed light, conceptually or mathematically, as...
Hello. I am doing a research paper on the relationship of specific heat capacity and refractive index of liquids. I am doing this by finding the relationship between specific heat capacity and concentration and refractive index and concentration. With this I can find a general trend and conclude...
Given the definition of the covariant basis (##Z_{i}##) as follows:
$$Z_{i} = \frac{\delta \textbf{R}}{\delta Z^{i}}$$
Then, the derivative of the covariant basis is as follows:
$$\frac{\delta Z_{i}}{\delta Z^{j}} = \frac{\delta^2 \textbf{R}}{\delta Z^{i} \delta Z^{j}}$$
Which is also equal...
Do we have any examples of physical constants appearing in topics that are focused more on abstract mathematics? For example, do the values of the physical constants ever appear in the results of papers on mathematics that are not focused on direct applications to physics? Could they do so if...
Homework Statement
The graph shows the response of a bare thermocouple
which has been subjected to a step change in temperature from 50°C to
10°C. Assuming that the bare thermocouple behaves as a single transfer
lag system, determine the mathematical relationship between the
temperature (T) and...
http://physics.stackexchange.com/questions/103904/size-of-a-photon
I can follow the equitations from John Rennie's answer in the above thread, but considering real 3D space, I don't understand how wavelength would make the location of a photon less precise. Can anyone explain that more?
For relativistic particle dynamics, there are two different approaches to choosing a Lagrangian that give the same equations of motion:
The quadratic form is:
\mathcal{L} = \frac{m}{2} g_{\mu \nu} U^\mu U^\nu
where U^\mu = \frac{d x^\mu}{d \tau}
This is for the action that involves...
Hi,
I have some trouble regarding the relationship between voltage and reactive power. From what I've read you control the amount of reactive power the generator is producing or absorbing by increasing or lowering the excitation of the generator.
I have some trouble getting my head around...
Hello there!
I'm currently doing some mathematical modelling at my work, and I have arrived at an interesting kind of circular relationship integral - and now I'm wondering about what to do.
The integral looks very innocent at first glance:
$$ \theta_s = \int\limits_0^{t_1} \omega (t) dt$$
So...
Homework Statement
A pure substance is placed into two containers of the same volume. Container 1 has twice the mass of pure substance of Container 2. After the containers are shut and both reach thermal equilibrium with the surroundings, what do we know about:
a) the pressure of Container 1...
Hi there,
I am in need of another's thoughts on this topic. I at first thought frequency is something that doesn't change and is inherent to the source, so then increasing the wavelength shouldn't lead to an increase in frequency, but an increase in speed. I realized later that this only...
Homework Statement
Homework Equations
i) F=ma=mv/t
ii) E=mv2/2
The Attempt at a Solution
Now based on equation 1 , I have concluded that the velocity gained is inversely proportional to m, and that so is the kinetic energy , I have seen otherwise.[/B]
Hello all,
I look forward to learning :)
EXPLANATION
There is a system with, let's say, 10 watt hours of energy available for use.
There is an inverse correlation between how much power we choose to use (energy use per second) and how quickly that systems energy will be completely drained...
Homework Statement
Homework Equations
none
The Attempt at a Solution
Here is my answer for part A of this question:
Part B:
This is where I am having trouble.
I took a guess at this, but it is probably completely wrong:
The corresponding graph shows the profit when different amounts...
Homework Statement
Is the amount of work depending on the mass?
Homework Equations
W=F*s
F=m*a
The Attempt at a Solution
attempt one:
because if you have a higher mass, it takes longer to make a certain object move over a certain distance, but it doesn't matter because time isn't measured. For...
Electromagnetic waves can be classically described by Maxwell's equations.
Photons can be described by probability waves.In this case, what is the relationship between the electric field and the probability amplitude?
Are they directly proportional to each other? What about the fact that one...
[Mentor's note: this was originally posted in a non-homework forum and therefore does not use the homework template.]
Hi everyone,
I'm a bit stuck on this question and hoping someone could give me the solution.
"A lump of lead, moving with a velocity of 22.0 m/s, is brought to rest. If 55.0%...
Hey guys, I know I still have a tread unanswered but I got a project in which I have to include some physical theory about the working of motors. I know P=V*I and also P=T*W where V is voltage, I is current, P is power, T is torque and W is angular speed. My question is, can I say V*I=T*W?. I...
Homework Statement
Find the general expression for the adiabatic relationship between P and V
Homework Equations
start with ##(\frac{∂P}{∂V})_s##
expression for adiabatic relationship between V and T: ##(\frac{∂V}{∂T})_s = \frac{-C_v}{\frac{RT}{V}}##
Relationship between S and T...
Homework Statement
edit: I figured out my mistake
Here's the entire problem. But I don't yet need help with all the steps. I'm getting off on the wrong foot (as usual)a We have shown in class that ideal gas adiabats have the form: ##P_I(V_i)^γ = P_f(V_f)^γ## with the heat capacity ratio: ##γ...
Homework Statement
I did an experiment involving the speed of sound at different temperatures. I placed two microphones at a fixed distance apart and I measured the time taken for a sound wave to travel between the two mics. I repeated this for different temperatures. I want to make a graph for...
Homework Statement
I'm working on a project right now, which uses laser beams and part of the project requires me to find a mathematical model which relates angle of projection to the intensity of the light. Does anyone know of an equation(s) which relates the intensity and angle together...
As the title says, how will installing a larger tire/wheel combination or altering wheel offset change the alignment with respect to caster, camber, and toe?
I know that the parameters are affected, but I cannot verbalize or visualize these changes. Feel free to use big words and jargon.
TIA!
Hi all, I am really confused about the relationship among these three properties and I cannot find an answer satisfying enough..
If frequency of incident light increases but intensity remains the same, the photocurrent will decrease. Does this mean that the new curve on the current vs. voltage...
Hi,
I am curious as to whether there is a relationship between field lines and magnitude of charge. For instance, is the sketch for the electric field of a +1.0 micro coulomb charge the same as the sketch for a +2.0 micro coulomb charge?
Thanks. All help is very much appreciated!
So my question is, if the bulk modulus change by 5%, what is the fractional volume change value? is it times 0.05 or divided by 0.05? or the fractional volume change still the same?
Homework Statement
A tuning fork with a frequency of 420 Hz emits sound with a wavelength of 0.82 m in air. If the temperature of the air increases, what will happen to the wavelength and why?
Homework Equations
The Attempt at a Solution
I know temperature affects speed but I am not so sure...
Homework Statement
I would like to derive an equation that relates the thermal conductivity to the pressure using the kinetic theory of gases. However, I assumed that thermal conductivity was independent of pressure.
Homework Equations
I know that P = 2N/3V (1/2mv^2)
Also:
I believe that...
4. Sound intensity is inversely proportional to the square of the distance from the source
The further from the source you are, the less intense the sound.
Suppose the sound intensity is 20 watts per square meter. (W/m^2) at 8 meters.
What is the sound intensity at 4 meters...
I have a very simple question that's been driving me nuts. It's biology context, but probably all the physics equates to normal positive displacement pumps.
The pressure in and volume of the left ventricle of the heart can be measured experimentally. (For example...
Trying to follow some text:
Given a Gaussian-like distribution for a wave packet, ie a symmetric distribution of $k_x$ about a mean value $ \bar{k}_x $. Making the change of variable $u=k_x - \bar{k}_x$, they write the Fourier transform as: $\psi(x,0) = \frac{1}{2 \pi} e^{i\bar{k}_x...
Homework Statement
For z = x+iy find the relationship between x and y so that (Imz2) / z2 = -i
2. The attempt at a solution
I attempted this in a few different ways (i.e. looking at the exponential and trig forms of complex numbers)... I settled on simple FOIL which gave me the following...
Homework Statement
https://dept.astro.lsa.umich.edu/~mmateo/Astr404_W16/WebPage/Assignment_Jan21.pdf
Homework EquationsThe Attempt at a Solution
Apologize for the long question. I was able to solve problem a and b. But for problem c, I was confused. I asked my professor and he gave me this...
ω1. Homework Statement
The following function represents a propagating wave function in a medium
f(x,t) = Asin(3π/ λ(x-ct) + a)
where A is the amplitude, λ is the wavelength, c is the speed of light in free space, and a is the initial phase.
(a) Plot the energy-momentum relation of the wave...
Homework Statement
Consider the diffusion of a drop of ink in a water vase. The density of the ink is ## \rho (\vec{r}, t) ##, and the probability ##P(\vec{r}, t)## obeys the diffusion equation. What is the relationship between ##\rho (\vec{r}, t)## and ##P(\vec{r}, t)##?
Homework...
Homework Statement
I am trying to understand the the following derivation:
Cv = (qv/ΔT) = (ΔU/ΔT) \\
Cv = (∂U/∂T)v \\
dU = CvdT
The Attempt at a Solution
[/B]
So here is what I understand so far. I understand that heat transfer q and temperature T are related by a direct...
Homework Statement
A testing device has the applied load located at the end of a loading bar. The loading bar is connected by a pin to the post. Find the symbolic relationship between the applied load(the "input" load) and the effective load applied the specimen(the "output" load).
Homework...