Specific Definition and 1000 Threads

Why SAR value at body is allways higher than at head?

Hello all! I would like to know what chemical/physical properties influencies the specific heat. For example, why are specific heat of metals smaller than the specific heat of water, and why do ice and steam have a smaller specific heat than liquid water do.

In a previous thread, I referenced an argument from the book the Scientist as Philosopher by Friedel Weinert, in which he talks about the reference frames of two relatively moving observers. He made a statement that I had't thought about before, but when I was reading it this time around a...

Hey all, I am working on a problem that goes like this: The cargo space of a refrigerated truck whose inner dimensions are 12 m 3 2.3 m 3 3.5 m is to be precooled from 25°C to an average temperature of 5°C. The construc- tion of the truck is such that a transmission heat gain occurs at a rate...

For a body at temperature T, the radiative energy per unit area E depends on 4th power of T. I can obtain expression for specific heat c by differentiating Stefan's law with respect to T. Would it be the correct way of approaching this problem? Or do I need to employ certain models from Solid...

The solution can be found at https://study.com/academy/answer/an-insulated-rigi... After using the two equations I can't see why (h2-h1)/(u2) should equal (T2)/(T1). Can someone explain why specific heat ratio is equal to temperature ratio?

I have been at this exercise for the past two days now, and I finally decided to get some help. I am learning General Relativity using Carrolls Spacetime and Geometry on my own, so I can't really ask a tutor or something. I think I have a solution, but I am really unsure about it and I found 6...

say I used a good insulator?

Given this problem I have calculated the partition function as $$z=1+e^{-\beta E_1}$$ And calculated the average internal energy as $$<U>=\frac{E_1 e^{-\beta E_1}}{1+e^{-\beta E_1}}$$ And thereafter taking the partial derivative of <E> with respect to temp. T the specific heat obtained is...

If ##N## is constant (per the partial derivatives definitions/ the subscripts after the derivatives) then ##G## is constant ##H - TS = constant## Taking the derivative of both sides with respect to ##T## while holding ##N,P## constant we get the following with the use of the product rule...

this is my attempt of a solution , but my only equation is should i convert Θ to Celsius , and if i did the specific heat of the other substance is greater , how is that if its inversely proportional with temperature ! . and the other Θ is 200 K so it should be less ?!

Hello, I would like to understand know how the lift coefficient ##C_L## versus AoA curve and the drag coefficient ##C_D## versus AoA curve are determined for the various tabulated NACA profiles. Are computer simulation run for the different profiles assuming a certain Reynolds' number? Or can...

P = 49000; R = 57 1/7%; T = 4 yrs; SI of 2nd year = ? R = 57 1/7% i.e 4/7. i.e Interest/Principle. Principle; 7 corresponds to 49000. After this how to proceed?

Homework Statement: An open tank with a rectangular side 1 m wide and 4 m high is filled with a liquid of variable specific weight, γ, with γ = 50 + 2y (N/m3), where y is measured vertically downward from the free surface. Find the magnitude of the force on the side of the tank. Homework...

Hi, In another forum someone asked how to find the kth digit of a large prime given in the form ##2^t-1 ## , where t is a 6-digit (decimal) number. I was thinking maybe using some SQL string function , though I am not sure if input strings must be entered explicitly. Can anyone think of some...

Hey everybody so I am a student and I am learning about failure analysis. So let's say I have a rigid body that is being kept in this position...there is a moment at A generated by a motor to keep the body in this position, working against the weight of the body itself and small wind force...

Twice I found the following derivation of ##E\propto v^2## in a little distinct forms. https://www.physicsforums.com/threads/the-final-explanation-to-why-kinetic-energy-is-proportional-to-velocity-squared.78484/#post-609992 The derivation is in post #9, if it is not shown properly. This...

Black powder has specific impulse of around 80s, while rocket candy has up to 130s of specific impulse. Does that mean I could replace the propellant in a BP cartridge with 80/130 of the weight in rocket candy and obtain the same performance in an idealized gun? (as in without considering...

i am nonplussed about how to proceed with this dilution, probably it is very simple.

Not attempt

Source = John R. Taylor, Classical Mechanics, page 651 + page 677 Trying to solve, A mass m is thrown from the origin at t=0 with initial three momentum p_0 in the y direction. If it is subject to a constant force F_0 in the x direction, find its velocity \mathbf{v} as a function of t, and by...

Hi, I don't understand why the author in calculating the expression for the specific heat, divides by ##1/V## (the total volume). Also, in calculating the fraction of modes with frequency in the range ##v##, ##v+dv## he divides by ##V## (eq. 2.65, 2.67) Thanks, Ric

If the comma means ordinary derivative, then ##(A_\mu A_\nu^{,\nu} - A_\mu^{,\nu} A_\nu)^\mu = A_\mu^{,\mu}A_\nu^{,\nu} + A_\mu A_\nu^{,\nu,\mu} - A_\mu^{,\nu,\mu} A_\nu - A_\mu^{,\nu}A_\nu^{,\mu} = A_\mu^{,\mu}A_\nu^{,\nu} - A_\mu^{,\nu}A_\nu^{,\mu} ##, where ##A## is some vector field...

I am working on some simulations to determine pressures for extremely high-pressure combustion events. The temperatures in these events can range anywhere from 3000 K to 6000 K. In order to do this I need to find valuers for specific heats of gases at these temp ranges as I know they vary to a...

I set up an experiment where I put a fixed quantity of water in a cylinder fitted with a movable piston. I slowly add heat to the system, as expected both the temperature and the volume will increase but the volume will not increase significantly (steep line), until some point where some gas...

The anthropic principle is a philosophical consideration that observations of the universe must be compatible with the conscious and sapient life that observes it. There are two main types of anthropic principle: Weak Anthropic Principle (WAP) and Strong Anthropic Principle (SAP) The Strong...

Summary: I found an old topic on this forum that describes a similar problem to what I am facing currently. I want to rotate an object with euler angle values, but the rotation has to be translated based around a specific angle. However, I do not fully understand the solution provided in that...

I'm interested in the following problem: given a random number n (n can be gigantic), how do we find a pair function+input(s) whose output is n such that the input(s) are relatively small in size? This problems arises in data compression; consider the bits that make up a file (or a substring of...

Dear Experts, We compute Cv for gases using the idea of equipartition principle and degrees of freedom. In case of a diatomic molecule, there are minimum 3 degrees of freedom (at very low temperatures) and maximum 6 degrees of freedom one of them being vibrational (at high temperatures. Does it...

Problem Statement: so we did an experiment. basically the teacher gave us each a cube of unknown metal and we had to figure out what it was using the specific heat. we put the metal in boiling water until it was 212C and then we put it in room temp water and we measured how much it heated the...

1. I am rather confused about the usage of Cp0 and Cv0 in the solutions to the question below: In the solution to the depicted question, the solution involves setting up the equation as follows: Q-W=me*he-mi*hi+m2*ue-m1*u1 -W=-mi*Cp*Ti+m2CvT2-m1CvT1 I don't follow for the second step. How can...

Relevant Equations: Specific Work Done: w = \frac{p_2 v_2 - p_1 v_1}{1-\gamma} (1) w = \frac{R}{1-\gamma} \times (T_2 - T_1) (2) Thermal efficiency: \eta _{th} = 1- \frac{1}{r_p ^ {\frac{\gamma - 1}{\gamma}}} = \frac{w_{out} - w_{in}}{q_{in}} = \frac{q_{out} - q_{in}}{q_{in}} (3) Context...

First, let me apologise if this is in the wrong thread, wrong place, or wrong forum. I've not had any good experiences so far getting an answer I can understand, because my maths education didn’t really prepare me to even begin to try to figure this one out! I'll try to explain the situation...

I am currently setting up a simulation for thermal hydraulic analysis of an AGR fuel bundle. However, the walls in this type of reactor, have a specific roughness that promototes turbulence which in turn provides better heat transfer characteristics. I am struggling to find data online to...

So, I am casually sifting through a chapter in a thermodynamics textbook talking about the multiphase process that pure substances go through. I understand how the P-v and T-v diagram works and that out of the three properties (specific volume, temperature and pressure), two of them are...

Hi, I am using fortran to read specific columns from a .csv file. the rows in each columns are different, so I wish to read columns wise with a do loop. say, I wish to read from A1 to D20 initially(4 columns of 20 rows), then later f1 to h35 (3 columns, 35 rows). how do I read particular columns...

Hello, I have a signal and got the FFT result of that. I have shown them both below along with the MATLAB code. May I ask if there is any method to find the time zone(s) in the signal that a specific frequency has(have) happened? The reason I'm asking this is that I want to specify the time...

Homework Statement 1.2.6. Supose that the specific heat is a function of position and temperature, c(x,u). (a)Show that the heat energy per unit mass necesary to raise the temperature of a thin slice of thickness deltax from 0°to u(x,t) is not c(x)u(x,t), but instead int((0->u)c(x,u’))du’...

I've been playing around with this function of two variables: xy (eax-eay)/(xeax-yeay ) where a is a positive parameter. Now, when x and y are very large and close to each other in size, this seems to easily lead to catastrophic cancellation and computational problems. One thing that seems...

I was assigned an example problem today and i can do the math, look at my tables and get the right answer no problem. What i want to understand, is why when specific volume increases for r134a, that it means its supper heated? My given value for sv was .1384m3/kg which is above the .09 in the...

I've just started using Mathematica and I'm still trying to get used to how things are properly done with it. I tried to do a calculation (this one: https://www.physicsforums.com/threads/lagrangian-of-a-driven-pendulum-landau-problem.965714/) and I had to neglect some terms in an expression. Is...

I read something several years ago and I would like to know if anyone here can help me identify where it came from. I've searched the Internet in vain. Lots of math / rogue wave articles but no hint of any such anecdote. Using my own language, since I don't recall the specifics of the anecdote...

Hi there! I have a problem that I cannot solve and I really need your help. This problem is connected to a single event held by an unnamed company and I am asking you to help me form an equation. Basically, the simple equation would be revenue-costs=profit/loss. I need to form an equation that...

Good afternoon I just have this little doubt: imagine the osculating orbit of Mars changing slowly in its elements along the centuries. The semi major axis changes, the period, etc. Is the specific angular momentum allways equal in all the osculating orbits Mars has in those centuries? Or does...

Homework Statement Prove Rijkl= k/R2 * (gik gjl-gil gjk) where gik is the 3 metric for FRW universe and K =0,+1,-1, and i,j=1,2,3, that is, spatial coordinates. . Homework Equations The Christoffel symbol definition: Γμνρ = ½gμσ(∂ρgνσ+∂νgρσ-∂σgνρ) and the Riemann tensor definition: Rμνσρ =...

Homework Statement I have delta H _solution, and also the mass of the solitd and q_water and q_reaction. Im using Dulong Petit to get MM but I need specific heat of the solid obviously. I don't have a final temp of the unknown solid, just the delta T for the water thanks for any help Homework...

The ans comes out (c) if I take specific heat at constt volume to be independent of temp. Whether the specific heat is always temp. independent for an ideal gas??

I am writing some automatic differentiation routines for Taylor series, and would like to verify my results for the value and first six derivatives of ##sinh## and ##cosh## evaluated at ##\pi /3##, and also ##tanh##, and ##sec^2##, evaluated at ##\pi / 4##. I have attempted to use this site to...

I am reading "Thinking Fast and Slow" (fantastic book by the way) and I ran across a statement that has me flummoxed. The justification for the statement was said to be "Bayesian analysis" so I looked into that and frankly it's just more than I want to get into so I'm wondering if someone can...

Why specific heat of solids and liquids doesn't change with change in temperature?