Specific Definition and 1000 Threads

I'm confused about what units are used, and what the specific heat of seawater is defined at? I found a website quoting, 'specific heat is about 3850 J/(kg C)' Is this correct, with these units?

Homework Statement The ice piece of 380 g was taken from the deep-freezer, temperature was -9,6 °C, and well insulated container to the being stone-cold ( 0 °C) water. Inside the Ice piece was small temperature detector. When temperature of the the ice piece had balanced 0 °C. part of the...

Hi, Working on a project, I am told to find the K,n value of a specific transistor (2n7000), given the spec. sheet. I know K,n can be found from the formula: I,d = K,n * (V,gs - V,tn)^2 I'm close, from the spec sheet, I can use a V,gs value and a corresponding I,d value, however not sure what...

Homework Statement \int dx/(x4 + 16) Homework Equations Hint: With a>0, x4 + a2 = (x2 + \sqrt{}2ax + a)(x2 - \sqrt{}2ax + a) The Attempt at a Solution I've plugged this into the equation, which leaves me with: \int dx/[(x2 + \sqrt{}2ax + a)(x2 - \sqrt{}2ax + a)] But now I...

Today, during class, our professor went through a simple example about Piezoelectricity. We have a cylinder with a trapped ideal gas and a piston which is part of a capacitor together with the bottom of the cylinder. The voltage across the capacitor is \Phi, and the charge is Q. The distance...

Homework Statement A 5.00-g sample of aluminum pellets (specific heat capacity = 0.89 J/°C · g) and a 10.00-g sample of iron pellets (specific heat capacity = 0.45 J/°C · g) are heated to 100.0°C. The mixture of hot iron and aluminum is then dropped into 96.5 g of water at 23.5°C. Calculate...

Given a set of 2D coordinates (real numbers, involves positives and negatives), I could calculate the (weighted) barycenter by simply using the logic with plain numbers. For the barycenter calculations, I sum all the values with respect to x-axis and y-axis separately, and then divide with the...

Imagine there are 2 space-probes in space. Both of them start their engines in the same time. The first space-probe has a very low level of thrust but a very high specific impulse. The second space probe has a very high thrust but a very low specific impulse. Both of them have an equal amount...

Homework Statement The specific Lagrangian for a cantilever beam is given by: \overline{L}=\frac{1}{2}m[\dot{u}^2(s,t)+\dot{v}^2(s,t)]-\frac{1}{2}EI[\psi ^{\prime}(s,t)]^2 where m,EI are mass and bending stifness, respectively. \dot{u},\dot{v} are velocities in u,v directions...

We have the parameters,current =10^-3A,V=15kv,number of electrons=6.25 X 10^15,velocity=7.3 X 10^7,specific heat capacity of the liquid=2 X 10^3,c=3 X 10^8,h=6.63 X 10^-34,mass of electron = 9.11 X 10^-31. Now the question says,in an x-ray tube having those parameters,find the rate at which...

First of all, hello everyone :) . Second of all, I'm looking for magnets that are brick-like. They need to be pretty strong. Dimensions, ideally, would be 1" x 1" x 2.5 - 3". Can I get rare-earth magnets that do this? I'm not sure where else I can post this, so if it's in the wrong...

is there any specific name for a coffee cup handle in mathematics?

Homework Statement A student wants to melt a 200 gram block of ice that is at minus 10.0°C and turn it into liquid water at 15.0°C. The student plans to do this by heating copper pellets to 100.0°C and then dropping them onto the block of ice in a thermally insulated container. How many...

Homework Statement 1.0 g of water at 28 degree celcius is placed into a 200g aluminium can at 300 degree celcius. What is the temperature of the aluminium can after all the water vapourises? Given the specific heat capacity of aluminium, 900 J/kg/degree celcius and water, 4200 and specific...

Homework Statement This is a problem I made myself and it's really confusing me. You have 100mL of water and place it in a calorimeter of low specific heat capacity. You put another 100mL of water in another calorimeter of high specific heat capacity. Assume in both instances that the water is...

So, I can't really find this limit: \lim_{T \to \infty} \ 3Nk {(\epsilon/kT)}^2 \frac{e^{(\epsilon/kT)}}{{(e^{(\epsilon/kT)}-1)}^2} This is actually the formula for the specific heat of an Einstein solid, which is pretty easy to derive but I haven't been able to calculate the limit to show it...

Hi, I am trying to calculate the amount of heat required to raise the temperature of a rubber sphere by 20 degree's Celcius within 10 seconds. The rubber sphere will be heated via radiation in a closed system. I have calculated the specific heat capactity, by using the formula q =...

Homework Statement write down the Lagrange-Charpit eqs for \frac{ \partial u}{ \partial x} \frac{ \partial u}{ \partial y} - y \frac{ \partial u}{ \partial x} - x \frac{ \partial u}{ \partial y}= 0 and use them to show \frac{ d^2 p}{ d p^2} = P assuming that u = x^2 when y=0...

Imagine the skyscraper and the very long rod placed on its top that rotates from horizontal position to upwards. http://img109.imageshack.us/img109/4817/fhfn.png I would like to know how is it possible to calculate/ascertain the maximal length and minimal width of the rod made of some...

Homework Statement So basically our teacher gave us a bunch of materials and told us to conduct an experiment including the notes on change of heat we took earlier in the week. This is what my group conducted. We acquired 125 mL of water that started at 21 degrees celsius. We then heated...

Why is specific rotation not a colligative property? i just read that it depends on concentration(gm/litre) but i feel that it should depend on molarity considering the fact that rotation is due to changes in molecular structure...do i have a point or am i just being silly ...can someone help me?

Homework Statement Find the specific acoustic impedance for a standing wave p=Psin(kx)exp(jwt) where p is a complex variable.Homework Equations z = p/u (all variables are complex) u = (A/rho_sub_0*c)*exp^(wt-kx)The Attempt at a Solution Approaching this problem it seems that I have all of the...

I need to confirm something about combinations: 1. I need to find the combinations of 5 out of 35. <=> 35C5 = 324.632 combinations. 2. Now I want to try to "fit" these 324.632 combinations of five numbers into sets of 6 numbers. To do that, I first find how many combinations of five numbers...

1. A pressure vessel of volume 100 liters is filled with 1 kg of liquid water and 80 liters of steam with a specific volume of 0.02 m3/kg. Determine a. The density of the liquid water in SI fundamental units b. The mass of the steam in grams c. The density and the specific volume of the system...

Homework Statement To find the ratio of the specific heat capacities of air (γ). Homework Equations PVγ=constant The Attempt at a Solution I performed the experiment a number of times to get an average for γ The experiment consisted of a container with release valve, a hand...

1.the Schrodinger’s cat on test 2.wave - particle two-phase nature 3.entangled state 4.God does not play dice 5.the Bell inequality Please advice about the above statement should be how to write correctly?

So I don't get the concept of specific heat. I'm doing an ODE problem and I've never even looked at science, not even in high school. The book defines the specific heat of a substance as: The ratio of the quantity of heat required to raise the temperature of a unit of substance by one degree...

Homework Statement A piece of metal of weight 50 grams is heated to a temperature of 100°C and then introduced into a calorimeter containing water at 14°C, the maximum temperature reached being 20°C. If the weight of the calorimeter is 5 grams, the specific heat of the metal of which it is...

My industry (tubular steel poles) standardly uses A572, Gr65 and A871, Gr65 for shaft design with the designs taken to the minimum ASTM defined Yield and using loading factors in the design. The A572 specification has for years listed all grades as "Yield Point". The A871 specificaion (which...

I just heard "Cherish" by the Association on the oldies station, and immediately flashed back to the Freshman welcome dance in HS. It was a VERY hot song, and it was the first song played at that sock-hop for the Freshman-Senior waltz. I got chosen by a friend's sister. Cute and chesty in her...

Dear Forum members, I have a bit confusion about the "Specific Heat at constant pressure". Normally it only varies with the temperature (As given by many book at their Appendixs). But these values are only given at 1 atm pressure and with a wide range of temperature. Most of the books...

mechanical (work) unit is J/kgK Heat unit is kcal/kgK what is this mechanical (work) unit, Heat unit ? I'm not able to understand it. please elaborate

In another forum that I frequent, I have been having a discussion where the state of quantum gravity research came up. Another poster claimed that one of the first thing that any gravity scientist checks for the theory is the theory's prediction for the precession of Mercury's perihelion. Now...

An ice-cube has a mass of 7.50 g. The ice-cube is at 0 °C. Heat from the surroundings reaches the ice-cube at an average rate of 1.25 J / s. How long does it take for all of the ice to melt? (specific latent heat of fusion of ice = 333 J / g) A 35.5 s B 55.5 s C 2000 s D 3120 s

The question involves testing the Specific Heat Capacity of an aluminum block, using the equation: Q = m x Specific Heat Capacity x Change in Temperature. Two experiments are performed using the same power of the heater and the same mass of the object and a very similar change in...

I constructing 3D shape of about 2 millimeters sized. Which kind of optical coating will give me 10 degrees of half view angle for reflected light in visual spectrum ? thanks Alex

Homework Statement A cylindrical disk has volume 8.97 x 10^-3 m^3 and mass 8.16 kg. The disk is floating on the surface on some water with its flat surfaces horizontal. The area of each flat surface is .640 m^2. What is the specific gravity of the disk? How far below the water level is its...

Hello. I am writing an encryption algorithm for a program and have decided to use a hill cipher. My problem is that for the hill cipher, I have to have matrices with very specific properties. How might I go about finding 3 matrices of size 4x4 such that all of the matrices are integer-only and...

Homework Statement The experiment was that we heated a beaker with water in it, and also a type of metal for around 5 minutes so that the metal becomes the same temperature as the water. We then dropped that heated metal into a stryofoam cup containing 189.10g of water in it. mass of...

http://www.tpub.com/content/engine/14105/css/14105_20.htm This website tells me that Specific Gravity is weight of substance/weight of equal volume of water or density of substance/density of water. Can someone explain how this is true? Density and weight are two different things so...

Why the specific volume of a liquid decreases with the increase in pressure at saturation temperature and why the specific volumes of vapor at saturation temperature decreases with increasing pressure??

Hi, We're trying to build a simple antenna that's able to pick up a frequency of 457 KHz from a maximum distance of 20 metres. I'm totally new to this stuff, so I looked up the yagi antenna and some formulas used to determine the length of the antenna, but the results I got were huge...

Homework Statement My math is horrible and I'm in an orbital mechanics class which I'm way over my head...my question is... "What is the specific mechanical energy, e, of an orbit with a semimajor axis of 42,160km" Homework Equations I used a formula that took -3.986x10^5 / 2x...

I am wondering why the nation is gathering under the flag of bullying in relation specifically to gays instead of attacking the issue of bullying in general? I was bullied in middle school, and everyone just told me that was the way it was. I hate that bullying of anyone goes on and wish...

A constand current of 1A is flowing through the Helmholtz coils. When the voltage is altered the radius of the deflection beam changes accordingly. The trend line analysis of radius vs. voltage graphs give an equation of the form y=0.005x+25. (Hint: graph is plotted by considering r^2 (m^2) on...

We did an experiment using a calorimeter in class, where we dropped a hot piece of metal into water in the calorimeter. We measured initial temp of metal + water, and the final equilibrium temperature. This allowed us to calculated the specific heat of the unknown metal (we also had the mass...

Hi, I just did a specific heat capacity test using a calorimeter, and the specific heat capacity I found (using heat gained = heat lost) is less than the real value. The problem is, I expected it to be more. I mean heat will be lost through the calorimeter, meaning that a greater amount of...

Homework Statement how can I calculate specific heat at constant pressure from mass specific heat and mole mass?

Homework Statement Consider a particle-in-a-box problem, involving a particle of mass m subject to a potential: V(x) = +∞ for X≤0 V(x) = 0 for 0<X<L V(x) = +∞ for X≥L |ϕn> are the eigenstates of the Hamiltonian H with the corresponding eigenvalues: En = (n^2)*(hbar^2)*(Pi^2) / 2mL^2...

Homework Statement The cream is kept at 5 ºC in the lorries. It is pumped into silos, where it is pre-heated before being pasteurized. The silos are jacketed, and hot water is pumped through the jacket. Assuming no losses, if 300 kg of water at 90ºC enters the jacket and exits at 60 ºC...