Specific Definition and 1000 Threads

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?

There are 118 elements known to man, and some scientists like Feynman think that element 137 might be the end of the Periodic Table. Isn't that oddly specific? To me, it feels like it is completely random and of no significance. What is going on here? Is there a constant that relates to this...

Hi, Sorry if this is too simple. I was given permission by an employee to access to the Wifi service, using my PC, at a FedEx store,i.e., I will not be using their computers. I thought this would be straightforward: I would be given the key/password and then just log on to the network. But then...

Homework Statement A researcher studies the heat transference between an iron block and an unknown substance, inside an adiabatic calorimeter. In successive experiences he puts inside the calorimeter the unknown substance, always in its solid state and with temperature θs = 20ºC, and the iron...

Homework Statement Weight - 200kg RPM - 5 Diameter - 6m Homework Equations Moment of Inertia I = (weight/9.8).r^2 Torque t = I * (angular velocity / t) Power = Torque * speed The Attempt at a Solution First I calculate Moment of Inertia Using I=(weight/9.8) * r^2 = 183 kg. m^2 Then I...

Hello, I was thinking about how a blackbody (and any other type of body) eventually reaches a steady-state, constant and finite temperature once the absorbed energy is equal to the emitted energy. The specific heat of a substance indicates the temperature change causes by the...

From a wiki's vis-viva equation page, it is given that the specific angular momentum h is also equal to the following: h = wr^2 = ab * n How can ab * n be derived to be equal to the angular momentum using elliptical orbit energy/momentum/other equations without having to use calculus or...

Homework Statement An object is placed on a slope with initial velocity v=0m/s. Angle of the slope is 30 degrees and the coefficient of friction (or friction factor, not sure how it's said in English) is given as u=0.1*(x/m) where x is the path traversed and m is the mass of the object. After...

Homework Statement A 4.80 kg piece of solid material is heated from 16.4C to 219C (3 s.f.) using 787 kJ of energy (3 s.f.). Assuming an efficiency of 0.383 for the heating process, and that the material does not melt, calculate the specific heat capacity of the material. Homework Equations...

Homework Statement A 4.96 kg piece of solid material is heated from 16.7oC to 234oC (3 s.f.) using 725 kJ of energy (3 s.f.). Assuming an efficiency of 0.342 for the heating process, and that the material does not melt, calculate the specific heat capacity of the material. m = 4.96 kg change...

Homework Statement Solution: Homework Equations dp/dz = -ρh Pressure varies linearly with the depth. The Attempt at a Solution Firstly, I have calculated the pressure at point B. PB = PA - (0.3m)*(1000kg/m^3)*(9.81m/s^2) PB = 88057 Pa Calculating the pressure at point C. However, my...

Homework Statement A 12.0 g sample of a metal is heated to 90.0 °C. It is then dropped into 25.0 g of water. The temperature of the water rises from 22.5 to 25.0 °C. The specific heat of water is 4.18 Jg-1°C-1. Calculate the specific heat of the metal. Express your answer in Jg-1°C-1 Homework...

Hello, In my professor's lecture notes she gives this example and I have a couple of questions regarding it:Let M = \mathbb Z/6\mathbb Z and f: M \rightarrow M, x \rightarrow x+1 the cyclical permutation of the elements from M. Then is G := \{id_M, f, f^2,f^3,f^4,f^5\} a subset from S_M...

i have been learning about using redshift to measure the distance of far-flung objects, but in all my research i never saw a specific unit used to quantify how redshifted an object is. to me it seems like an oversight, because such a unit would be very useful for the study of distant galaxies...

Homework Statement [/B] Using Gauss law, Since there has been no mention of which type of charge density we have to find out I assumed it to be surface charge density since Gauss Law is in surface intergration , and I don't think there is any need to doing integration since the options given...

1. The problem What is the resultant temperature when 100g of steam at 100°C is passed through 500g of ice at -20°C.Homework Equations Q=mCDeltaT[/B] The Attempt at a Solution I am not sure whether both the quantities will combine to from water

Someone asked me this question. The numbers are real. İn Turkey there are 957 cities where Loto is drawn every week. In the last 5 years the big prize was drawn at one location 26 times. What is the probability that a single location will get the big prize 26 times in 5 years. I think, though...

Homework Statement If Cp for an ideal gas is 35.4 J/mol⋅K, which of the following is Cv for this gas? a. 12.5 J/mol⋅K b. 20.8 J/mol⋅K c. 29.1 J/mol⋅K d. 27.1 J/mol⋅K e. 43.4 J/mol⋅K Homework Equations ΔH = ΔE + Δ(PV) = Q + W + Δ(PV), and for ideal gas, ΔH = nCvΔT + Δ(nRT) = nCvΔT + nRΔT =...

Homework Statement I'm a little bit stuck with this exercise.A small body with temperature T and emissivity ε is placed in a large evacuated cavity with interior walls kept at temperature Tw. When Tw-T is small, show that the rate of heat transfer by radiation is $$...

Hi all, I do an calorimeter experiment at temperatures around 40 mK. To get more grip on the time constants that are associated with the heat flows, I calculate the thermal resistance as well as the heat capitance of the materials in the set-up. We assume that Newton's law of cooling is the...

For the first time in my lime I am not able to find home page for well-known and respected western periodical. I am looking for the paper titled «Définition covariante des équilibres thermodynamiques» by J. M. Souriau published in Supp. Nuovo Cimento, 1, I , 4 (1966) pp. 203-216 (given the fact...

Homework Statement A problem will ask for an amount of substance in kilograms to be raised to a certain temperature and the specific heat be given in J/g*K. The amount of substance is not required to be converted to grams to match the units in the specific heat to get the correct amount of...

Hello, I have been trying to solve this problem but I can't seem to find a way. Given are ##n## cards and each card can show one of two values: M or K. How many possible permutations are there in which there are as many cards with M as there are with K? Given that ##n## is an even amount of...

Homework Statement Homework Equations Cv=(f/2)R The Attempt at a Solution I have no problem getting the right answers. My question is this: If Cv=72.254 and if Cv = (f/2)R, that implies that f = 17.381. I understand that f represents the gas particle's degrees of freedom. How does this...

I have an acquaintance who's building houses for Purple Martins. He has audio he wants to play between 4AM and 8 AM local time that's supposed to be a dawn song for the birds. He's seeking a way to automatically play this audio on loop. I'm sure there are a million easier ways to do this, but my...

I'm looking for volunteers with technical skills in 3D animation and rigging with programs like nifskope, to help me get this Blender 3D model into an equippable/usable item the PC video game Fallout 4. Read the description for better information...

Homework Statement I want to read only specific lines from a file using fortran code. Homework Equations Fortran code The Attempt at a Solution I have a dummy.txt file wrote 7 5 6 4 5 6 9 10 14 19 I want read only values between lines 5 to lines10. But when I use print statement, the value...

Homework Statement The task is to find the uncertainty of the magnetic field, B. The magnetic force is plotted against current, so that the slope of the resulting line of best fit is LB, where L is the length of the conductor and theta is constant at 90 degrees (thus sin(theta) = 1). The...

Homework Statement A copper pot with a mass of 0.500 kg contains 0.170 kg of water, and both are at a temperature of 20.0°C. A 0.250-kg block of iron at 85.0°C is dropped into the pot. Find the final temperature of the system, assuming no heat loss to the surroundings. Homework Equations Q =...

Homework Statement Homework Equations The Attempt at a Solution I don't understand how the solution got its values, not from the tables right? because I couldn't find such value from all of the tables. Since the pressure is less than the saturated pressure at given temperature, it is in...

Homework Statement Heated iron with mass of 55.0 g was added to 100 mL of water at 20 degree Celsius. Assuming no energy transfer to the surroundings and that the final temperature of the system is 42.7 degrees C, calculate initial temperature of the iron. Mass of Iron = 55.0 g mass of Water =...

Create a class DecimalN which holds decimal numbers using dynamic arrays. Implement a constructor DecimalN::DecimalN(char* decimal) so that it can be created like for example DecimalN number("23.5698"). Create two class functions (methods) that given the number n it shift the number n places...

Homework Statement Here is the original question (just read the English version). Homework Equations Q = mcθ Specific heat capacity of water, c = 4200 J/kg °C The Attempt at a Solution I did Q_(absorbed) = Q_(released) mcθ = mcθ mθ = mθ And I solved for the final temperature, which is...

Homework Statement Homework EquationsThe Attempt at a Solution I have identified that only the specific enthalpy for stream F can be found from literature values, whereas the specific enthalpy of other streams are unknowns. The specific enthalpy of streams S, V1, C1, C2 and V2 are unknowns...

Hi folks, here's a thought/conceptual question I've been wondering about. What is the maximum theoretical specific energy (IE Joules/kg or equivalent) for energy stored in the electric field of a capacitor? I know the energy stored in a capacitor is given by U=C V^2/2, and the mass of the system...

I have once again come across a smoke detector which requires not only a specific type of battery (9V alkaline) but also a specific model (in this case Duracell MN1604) to be used. I had a similar problem with a CO detector about a year ago (which came with a list of about 10 models that should...

Homework Statement https://i.imgur.com/f2vSXtq.png Homework Equations https://i.imgur.com/Kjy1Tzh.png The Attempt at a Solution In this question, the pressure is different at different point, in other words it is not constant throughout the system. Why the solution use c(p) (or "enthalpy" h...

My doubt it is simply if have other reason to don't use this principle for the specific heat of diatomic gases. Homework Equations $$U=NkT=nRT$$ $$u_n=\frac{U}{n}=RT\text{ molar energy}$$ $$u_N=\frac{U}{N}=kT\text{ average energy}$$ $$Z=\sum{e^{-\omega_i/kT}}\text{ with $\omega_i$ particular...

Hi, could anyone tell me, if they have any ideas as to, what materials could be combined to produce a material with two characteristics- electrical conductivity of about 10 S/m and magnetic permeability of 7500. Thanks in advance.

Hello, My name is Hugh Carstensen. I am a CSE undergrad at the Ohio State University. I recently secured a position designing and assembling an automated camera-rig for digitization of archival works in the Knowlton School of Architecture. The rig will be powered by a number of small stepper...

Hi, I want to simulate a forced convection cooling problem. Air at ambient temperature is forced through a fan into a system to cool electronics and I would like to assess the temperature of the outlet air. Actually I'm interested in the delta between the ambient and outlet temperature. This...

Homework Statement A cylinder with a heavy ram/piston contains air at T = 300 K. Pi = 2.00 * 105 Pa, Vi = 0.350 m3, Mr = 28.9 g/mol & Cv = 5R/2 (a) What's the Molecular Specific Heat of an Ideal Gas, with a constant volume, computed at J/KgC ? (Cv) (b) What's the mass of the air inside the...

Homework Statement Consider a system formed by two phases of a substance that consists of a single class of molecules. Determine the specific heat ##c## of a vapor pressure and temperature ##p## ##T## on the curve of liquid-vapor equilibrium. Consider the steam as an ideal gas. Data: ##c_p##...

Homework Statement Please look at the below images which is the derivation of the relation between the internal energy of an ideal gas and the molar specific heat at constant volume. (Snaps taken from Fundamentals of Physics Textbook by David Halliday, Jearl Walker, and Robert Resnick) As...

Homework Statement Let ##A,B## be subgroups of a finite abelian group ##G## Show that ##\langle g_1A \rangle \times \langle g_2A \rangle \cong \langle g_1,g_2 \rangle## where ##g_1,g_2 \in B## and ##A \cap B = \{e_G\}## where ##g_1 A, g_2 A \in G/A## (which makes sense since ##G## is abelian...

Homework Statement A satellite to reflect radar is a 3.5-m-diameter, 2.0-mm-thick spherical copper shell. While orbiting the earth, the satellite absorbs sunlight and is warmed to 50 °C. When it passes into the Earth's shadow, the satellite radiates energy to deep space. You can assume a...

It is commonly known that the solution to the brachistochrone problem is a cycloid. However, in order for a solution curve to be a cycloid, the ratio between points A on the y-axis and B on the x-axis has to be r/pi*r, since that is the ratio between the "height" of the cycloid and half of its...

I have been refreshing my fundamentals. Average specific heats are confusing for me. Why they are average? Are there different values for them so the averages are taken? Would you please explain this? Source: Fluid Mechanics Fundamentals and Applications by Çengel/Boles. Thank you.

Homework Statement 300 kPa pressure and v=0.5 m3/kg. The state is fixed. I should find the temperature and quality if defined. Table values for temperature T P vf vfg vg 130C 270.1kPa 0.001070...