Specific Definition and 1000 Threads

Does the value of specific heat change with phase? If yes, why so and what are its values for Al in liquid and solid phase.

I was reading an article on Pseudomonas syringae and how removing a gene called inaZ from it's DNA will allow it to be sprayed on crops to prevent the crops from freezing during the winter. How is the inaZ gene removed from the DNA? I'm thinking that they use restriction enzymes that cut out the...

Homework Statement A saucepan of thermal capacity 500J/degC contains 5kg water at 20 degrees celcius. How much energy is required to raise the temperature of the saucepan and water: a) to 60 degrees b) by 60 degreesHomework Equations Q = mcΔt mcΔt = mcΔt The Attempt at a Solution First I just...

What does the author mean here when he says How does a massive particle have a specific chirality? I learned that the only massive single chiral fields are the ones with Majorana mass. Dirac fields are a mix of left-chiral and right chiral fields, they do not have a specific chirality. Is...

Hey guys. I need help figuring out how to do this problem. I have a test tomorrow and i am currently studying. I would like to know how they got this answer. I'm completely stumped and need help so thanks in advance! Here is the question: http://img405.imageshack.us/img405/624/physicsv.jpg...

Homework Statement Consider phonons propagating on a one-dimensional chain of N identical atoms of mass M interacting by nearest-neighoour spring constants of magnitude C. a) Show that the Debye frequency can be written as \omega_{D}=\pi(C/M)^{1/2}. b) Show that when the temperature is...

Homework Statement Calculate the change in the enthalpy of argon, in KJ/kg, when it is cooled from 100 to 25 °C. Homework Equations \Delta h = c_{p} \Delta T Where \Delta h is the change in enthalpy, c_{p} is the specific heat, and \Delta T is the change in temperature. The Attempt at a...

Homework Statement A block of mass 'm' is placed on an inclined plane which has an adjustable angle with the horizontal. The angle is increased slowly from zero until the block just starts to slide. This angle is called the critical angle, θs. Express the coefficient of friction in terms...

A bath contains 100kg of water at 60C. Hot and cold taps are then turned on to deliver 20kg per minute each at temperatures of 70C and 10C respectively. How long will it be before the temperature in the bath has dropped to 45C? Assume complete mixing of the water and ignore heat losses. I've...

Homework Statement A cube of gold is heated to a temperature of 94.2 degrees celsius, and then submerged in 31.3 mL of water at an initial temperature of 28.7 degrees celsius. If the final temperature of the water is 45.6 degrees celsius, calculate the volume of the cube of gold (s=0.130...

Homework Statement there is a bath of 160L of water at 41oc (shc 4000). A rock of 15kg is dropped into the bath at 250oc with shc of 2000 What temperature does the water end up at? Homework Equations Q=cmT The Attempt at a Solution Very sorry but I don't have a clue. Not...

Homework Statement Estimate the precise value for the specific heat of a nitrogen molecule at T=13.6K Homework Equations I'm pretty sure the correct equation is: Cp = (7/2)*R + R((hv)/(kT))2 *((e(hv/kT))/(e(hv/kT)-1)2 So R=8.314 J K-1mol-1 T=13.6K h=6.626*10-34m2kg s-1...

Hello everybody, I have a shape (polygon) made up from pixels (squares) similar to the image below. I need an algorithm to cut it into "lines" i.e. shapes of 1x[1..20] pixels. The lines should not be necessarily straight, but they should fill the entire area. Any ideas on where to start...

Hello everyone, as the title suggests I'm in need of finding some specific vendors or catalogs for a few particular items needed in my design project. My University will be taking care of the bill, so while I would appreciate modest cost expenses, it would benefit my college to have some of...

I was going to post this on Earth-forum here but I thought that you guys here can help me better with this. I'm trying to get the radius of Earth on every latitude degree from 0° to 90°, knowing 0° at Equator is ~6378,137km and 90° at North/South Pole is ~6356,7523km (source Wikipedia). In...

Homework Statement To determine the Specific heat of an oil , an electrical heating coil is placed in a calorimeter with 380g of the oil at 10C. The coil consumes energy(and gives off heat) at the rate of 84W. After 3min the oil temperature is 40C. If the water equivalent of the calorimeter...

Homework Statement A 1m^3 container is filled with the following -).12 m^3 of Diamonds -).15 m^3 of sand -).2 m^3 of petroleum at 20 deg Celcius -).53 m^3 of air 2 20 deg celcius and 1 atm pressure Find overall specific volume and density of container Homework Equations...

Homework Statement See attachment "problem". Homework Equations See attachment "data" The Attempt at a Solution Can someone tell me what values to plug in for the equation R/M integral (a+bT+cT^2...). The solution doesn't show this step, so I have no idea the numbers they used to...

1. What is the value of Q in this problem? Is it a value that's stated in the question or does it need calculating? A sample consisting of 5 moles of an ideal gas at a temperature of 300 K and a pressure of 1.00 × 105 Pa is heated to a temperature of 500 K at constant pressure. The amount...

Homework Statement Part a. A 500 W kettle contains 300g of water at 20°C. Calculate the time it would take to raise the temperature of the water to boiling point. Part b. The kettle is allowed to boil for 2 minutes. Calculate the mass of water that would remain in the kettle. State any...

What is the the relationship between the specific heat capacity and power (e/t) required to raise the objects temperature? Of course the energy required increases, but does the time it takes change also?

Here is a good question for maths enthusiasts. I really find this sum very tough. Any help, advice or guidance for this question will be greatly appreciated. find the product upto n terms (1+(1/2^2)) . (1+(1/3^2)) . (1+(1/5^2)) . (1+(1/7^2)) . (1+(1/11^2))...upto n terms Where the nth...

Can the specific heat capacity be negative? Is there any substance for which i have to add heat to decrease its temperature? By the way,why specific heat capacity has the word "capacity" in it? Is there any physical significance to it or it is simply traditional(historical)?

u denotes internal energy; v denotes specific volume; T denotes temperature.

I am surprised by the result when I estimate the specific heat of the plasma produced by heavy ion collisions in the LHC: C(plasma) ~= 2e5 J/(g-K) (Details below.) This is ~1e6 times greater than C(lead)=0.13 J/(g-K) (1). Did I make a mistake? If not, can the physics experts who read this...

Recombinant dna technology-[how are specific genes chosen]?? IN recombinant dna technology,certain segments of dna are removed from one organism and put in another.How are are specific portions of DNA removed from certain animals and fused into others?? More importantly,how do scientists know...

How can i determine Specific heat capacity of Water cpv if i know all variables If i use this equation: [(mi1 + mi2 +mv)cpv + mg*cpg]dT/dt = H mi1 = mass 1 dT/dt = 0.05 cpg = 890 J/(kg*K) mi2 = mass 2 mv = mass 3 H = 300 W masses are arbitrary numbers Its cpv that...

Homework Statement An unknown metal with C=3.6 Mass=150g Temp=160c is added to copper container(85g) filled with water(105g) both with an initial temp of 20c I have to find the final temp of water,container and metal Homework Equations none given but I assume it will be E=Cm(t1-t2)...

Homework Statement Heating a .8 kg disk of iron from 20 C to 400 C, but the specific heat capacity changes from 456 at 20 C, to 615 at 400 C. It hints that I'm supposed to find the average to solve the equation. Homework Equations E = mC(dT) The Attempt at a Solution I have a...

Given an ODE in the form of f(t)y''+g(t)y'+h(t)y=0 If all I am looking for is the y(t) at a specific value of t and NOT the general solution, can I just plug in that value of t into the original ODE and then solve it analytically or is a numeric solution the only way?

What force is necessary to just barely submerge (push Mary under fresh water) Mary if her average specific gravity is 0.95 after taking a deep breath and her weight in air is 660 N? F=mg ; Force of buoyancy=ρgV; F=mg 660/9.8=mass of air mass of air=67.3 force of buoyancy= 67.3 x...

okay so I am just slightly confused about current and about how it is drawn from a power supply, so say we have a device that requires 5 volts and uses a max of 550 milliamps, and now let's say that the power supply used is rated at 5 volts, but 32 amps, does this mean that the power supply...

Homework Statement Why may the specific rotation of a sample of (R)-(+)-limonene be less than the literature value of (R)-(+)-limonene. Assume that there are so (S) enantiomers present. Homework Equations The Attempt at a Solution There are no (S) enantiomers, but there are some...

Homework Statement When a car brakes, an amount of thermal energy equal to 112500J is generated in the brake drums. If the mass of the brake drums is 28 kg and their specific heat capacity is 460.5 Jkg^-1K^-1? A piece of iron of mass 200g and temperature 300°C is dropped into 1.00kg of water...

This is a common subject I'm sure, but for reasons unknown this information is difficult to find. I have written my statement of purpose, all that remains is to customize it to each institution that I am applying to. How did you handle this? Did you talk about faculty you think would be...

Hi, I got my BS in Physics/Math in May, but left on a 1-2 year bike trip that is delaying my applying to graduate schools. I plan on applying next fall for admittance fall 2013. My question is: how necessary is it to have specific research interests when applying to graduate school? I am...

Homework Statement The specific heat of lead is 0.03 cal/g*C. 300 grams of lead shot at 100* C is mixed with 100 grams of water at 70* C. What is the final temperature of the mixture if the container is insulated. Homework Equations The Attempt at a Solution Q1 = c1m1(Tf - 100)...

I have completed a difference table for 4 points, x0, x1, x2, x3 and found the third degree poly that goes through these four points. Now I need to know how to make the polynomial of second degree that interpolates x0, x2, and x3. Do I just need to remake the table for 3 points, now excluding...

Homework Statement A sample of a diatomic ideal gas has pressure P and volume V. When the gas is warmed, it's pressure triples and the it's volume doubles. This warming process includes two steps, the first at constant pressure and the second at constant volume. Determine the energy...

hi all! i'm trying to figure out how much water i need to heat and to what temperature, to end up with 1 cubic meter of steam at 70atm. i used the calculator found here: http://www.efunda.com/materials/water/steamtable_sat.cfm i punched in 70atm, and got the following data: Temperature...

Specific & Latent Heat - Heat required to turn water in Aluminum Tray --> Ice Homework Statement 200 g Water (l) is contained in an Aluminum ice tray that has a mass of 340 g. Both is at 18°C. How much heat (Q) must be removed to turn the water into ice at -15°C? Aluminum m[FONT="Times...

Homework Statement A 28.2 g sample of nickel is heated to 100 degrees C and placed in a coffee cup calorimeter containing 150g of water at a temperature of 13.5 degrees C. After the metal cools, the final temperature of the metal and water is 25 degrees C. Calculate the specific heat...

Homework Statement A mixture is made by adding 75g of an unknown liquid at a temperature of 25 degrees Celsius to 60g of water at a temperature of 90 degrees Celsius. The final temperature f the mixture is 65 degrees Celsius. Calculate the specific heat capacity of the liquid. What is the...

Homework Statement what is the different in term of definition between Heat capacity and Specific heat capacity ? Homework Equations Q=mΔTC →C=Q/mΔT The Attempt at a Solution Specific heat capacity is the amount needed per unit mass of material so is a number independent of the...

Homework Statement How much heat is required to change 1.75 L of Ethyl Alcohol (C2H6O) at -50.0°C to a gas at its boiling point? Ethyl Alcohol V = 1.75 L Ti = -50°C 46 g/mol density = 0.789 g/cm3 boiling point = 78°C specific heat (c)= 2400 J/kg*C° Heat of Vaporization (Lv) =...

Homework Statement A uniform solid ball rolls down a slope. If the ball has a diameter of .5m and a mass of .1 kg find the following: The equation which describes the velocity of the ball at any time, given that it starts from rest. Homework Equations I've tried using energy...

Hopefully this is a really simple question to answer. A problem I have uses the following information: The specific heat of air = 1.05 kJ/hg-C. Does anyone know what the hg-C stands for? I know specific heat is usually expressed in terms of J/C, so this is confusing me.

Hi, I am struggling with this strange problem. I have to find pairs of positive integers that satisfy two specific conditions. 1. you can’t go from one pair to another by subtracting/adding the same number to both members of the pair. 2. You can’t go from one pair to another by...

hello, If I had a substance (k) and heated it from Temperature1 to Temperature2, for z seconds, is there any (simple) equation that would give me the temperature (x) of this substance at the end? (knowing, of course, the substance's specific heat(C)) I found that: Q(energy exchanged during...

Homework Statement The three blocks shown are relased at t=0 from the position shown in the figure. Assume that there is no friction between the table and M2, and that the two pulleys are massless and frictionless. The masses are: M1 = 2.00 kg M2 = 7.00 kg M3 = 4.00 kg Calculate the speed of...