Internal Definition and 957 Threads

i have attached a past paper question on internal forces and stress-strain, please help!

Homework Statement Light is incident normally on the short face of a 30-60-90 (degree) prism. A drop of liquid is placed on the hypotenuse of the prism.If the index of the prism is 1.68, find the maximum index that the liquid may have if the light is to be totally reflected. Homework Equations...

If a cell is connected with an external resistor of 6V and a switch and a voltmeter is connected across the terminals of the cell which reads 2.6 V when the switch is open and 2.4 V when the switch is closed, how do you find the emf and the internal resistance? so far i tried doing: V = IR...

The task is to derive an expression for the heat capacity of a system at constant volume and show that at high temperatures it is inversely proportional to the square of temperature. As far as I'm concerned the relation between internal energy and heat capacity is: Cv=dE/dT However with...

Why does total internal reflection happen in glass?

Homework Statement A gas sample heated in a cylinder used 650 kJ of heat. A piston that compresses the gas does 800 kJ of work. What is the change in internal energy, ΔE, of the gas during this process Homework Equations ΔE = q + w The Attempt at a Solution ΔE = q + w ΔE =...

Hmm. This is another thing I'm unsure abt. When some mechanical energy is converted to internal energy, can we still say that energy is conserved? Can the internal energy be negative? Thanks for answering my qns :)

Homework Statement I performed a lab where we designed an electric circuit on paper and then calculated the Current, Power, and Voltage for each of the resistors. We used one power supply. Then we built the circuit we designed and then measured the actual Current Power and Voltage for the it...

Hi all, I am new to this forum and COMSOL. I want to define the temperature at the common surface of two cylinders in contact. When I model the cylinders, the common surface (middle surface) is not active for defining any BC. Please tell me how can I do this in COMSOL. Thanks.

A cup of water is scooped up from a swimming pool of water. Compare the temperature T and the internal energy U of the water, in both the cup and the swimming pool. a) Tpool is less than Tcup, and the U is the same. b) Tpool is equal to Tcup, and Upool is less than Ucup. c) Tpool is equal to...

How do you combine two separate volumes of an ideal gas which are at different temperatures pressures and volumes and then work out the change in internal energy? I have been trying to get my head around this without success.

Ok, I know this question is very old, and it has probably been answered by now, but if the electron does not have an internal structure (like the proton for example), how does it maintain itself as an entity? Why does it not disintegrate? I've asked this question a couple of times before ,and...

Consider two adjacent transparent media. The speed of light through Medium 1 is v1, and the speed of light through Medium 2 is v2. If v1<v2, then total internal reflection will occur at the interface between these media if a beam of light is? I said incident in Medium 1 and stikes the...

I was searching a clip in Youtube and got: Is this really funny?

Consider a gas contained in volume V at temperature T. The gas is composed of N distinguishable particles at zero rest mass, so that the energy E and momentum p are related by E = pc. The number of single-particle energy states in the range p to p + dp is 4\pi Vp^2 dp . Find the equation of...

I note that in many case, we always use the constant-volume specific heat to calculate the change of internal energy. For example, in a adiabatic process (P1, V1, T1) to (P2, V2, T2), since internal energy is state variable, we always like to build a fictitious isochoric process from (P1...

Hello, while studying thermodynamics I was wondering why, in a system where the pression is not univocally determined (for example in irreversible trasformations), to measure the total work of the trasformation, we use to consider only the external forces. I mean, this sounds conceptually right...

Hello, I know that something around 65% of the potential energy stored in fuel is lossed in an engine through heat. I am trying to find exactly how its lossed, I know some is through piston friction, and some is lossed through the exhost, but I can't find how much is lossed for each...

If I set up a coil with thin wire, push a magnet through it, and connect either end to a voltmeter (in series), then is this an accurate way to measure the total voltage? I might not be phrasing this right, so ask me to clarify if I should. I'm guessing that you can't just simplify a circuit...

PROBLEM: Some warm water is mixed with ice and the ice melts. Assume that the entire process happens in an insulated box. Does the internal energy of the combined (ice+water) system change? Does the entropy of the combined system change? Considering that the ice and water as separate...

Homework Statement Two moles of carbon monoxide (CO) start at a pressure of 1.2 atm and a volume of 30 liters. The gas is then compressed adiabatically to 1/3 this volume. Assume that the gas may be treated as ideal. What is the change in the internal energy of the gas? n = 1.2 atm V2...

Homework Statement From the beginning of chapter 21 Haliday, Resnick and Walker: `Suppose that you return to your chilly dwelling after snowshoeing through the woods on a cold winter day. Your first thought is to light a stove. But why, exactly, would you do that? Is it because the stove...

Hey I am very new here (litrally signed up 10 mins ago after trying to search the net for this problem) heres what it looks like in my c/w so far I've worked out the total resistance of the open circuit but the next question is asking i attempted to use ohms law but that would of been...

Internal and thermal energy vs Temp? Hello I am a layman who is seriously trying to grasp the concepts and principles of physics to understand the workings of the world. I have seen the equations for deriving Internal Energy and Thermal Energy but lack the math to apply them or be sure if...

how to find the point in the cylinder where kinking will form ?

Homework Statement Compare the Internal (or Thermal) energies of the different containers sketched below. Choose the correct ranking of the internal energies provided. Each container contains H2 molecules with the shown amount (the number of molecules) at the same temperature. a) A=B=C=D...

Homework Statement When you take a bath, how many kilograms of hot water (49°C) must you mix with cold water (12°C) so that the temperature of the bath is 36°C? The total mass of water (hot plus cold) is 191 kg. Ignore any heat flow between the water and its external surroundings. Temperature...

Boiling Internal Energy - URGENT A quick question: dU = dQ - dW What are dU, dQ and dW during Boiling? I thought: -the particles do work, hence dW is + -dU increases as particles gain more energy so dQ = dU + dW - showing that heat flows in. Which made sense to me. Or is...

Is there a theory about the relationship, a ratio perhaps, for a Black Hole's event horizon dia. and its actual internal mass dia.? It would seem that there must be a physical mass in there somewhere, of some particular size for a given mass. This ratio may vary proportional to the mass of the...

When switch S in the figure is open, the voltmeter V of the battery reads 3.07 V. When the switch is closed, the voltmeter reading drops to 2.95 V, and the ammeter A reads 1.70 A. Assume that the two meters are ideal, so they do not affect the circuit. Find the value of the emf. (see picture...

Hi all, Why the probability of knocking out k-shell electron in internal conversion is higher? Please don't mention here that k-shell is nearer to nucleus. Thanks

Hi all, I'm am reading chapter 3 of Tinkham's "Introduction to superconductivity". At some point several thermodynamic quantities are considered (sec. 3.6.3). In particular fig. 3 compares the internal energies of the superconducting and normal states, showing that they are different below...

Homework Statement A torch bulb is marked 2.5V and 0.3A. When it is connected to a dry battery of e.m.f 3.0V the correct p.d of 2.5V is produced across it. Calculate the internal resistance if the battery.Homework Equations I=V/R?The Attempt at a Solution It's on paper - sorry!Answer = 1.67 -...

Homework Statement Provided that the input resistance of the DMM is much larger than the resistance values in the circuit to which it is connected, the DMM will not draw a significant current. Estimate the input resistance of the DMM by connecting the 10 M resistor supplied in series with...

I am kind of confused by the conflict of the following two concepts. If I understood correctly, internal energy of a system is independent of the volume occupied by the gas molecules. This is because the gas molecules are assumed to be ideal and therefore have no intermolecular interactions...

Homework Statement A battery having an emf of 9.30 V delivers 103 mA when connected to a 60.0 ohms load. Determine the internal resistance of the battery. Homework Equations V = E - IR The Attempt at a Solution i plugged in 9.3 for V, .103 for I, and 60, for R... and i got...

I remember seeing a commercial advertisement in which a hamster in a cage moved itself towards a desirable item (food or something) that its owner had on the counter by throwing itself against the side of its own cage. Would this really be possible? On the one hand it seems like there are only...

Hi All, I would like to know what is the precise meaning of the internal resistance of a DC source of voltage. Does it have some chemical contribution (as for instance, mean time for the reaction to occur, mean velocity of difusion of charge through the acid solution, or something like...

How can I go about calculating internal resistance? I have variables I, R, and V but no idea on how to find the 'internal' resistance. Is this some sort of special case?

Homework Statement Devise a NON DESTRUCTIVE scheme to measure the resistance of the 0-1mA meter that is provided in the lab. You may make use of an external power supply (or battery) and other circuit components such as resistors to make your measurement. Design your measurement scheme so that...

Homework Statement Calculate internal resistance of meter. There is a 10V power supply with a variable resistor connected in series. The meter will be connected across the resistor. I adjust the resistor until the reading in the meter read about 5.37V. The value of resistance is 15 ohms. How...

In Diamonds, light that enters gets trapped within due to total internal reflection, defined as: Total internal reflection is an optical phenomenon that occurs when a ray of light strikes a medium boundary at an angle larger than the critical angle with respect to the normal to the surface...

[Solved] Total internal reflection, underwater light? Homework Statement A point source of light is at the bottom of a koi pond, at a depth of 0.525 meters. What is the radius of the circle of light formed on the water's surface? Take the index of refraction of water to be 1.33. Hint: Some of...

Does a persons attitude, or way of life affect their internal body? I don't mean it as a couch potato will be weak. I mean it as a picky person will they have allergies? Will a germ phobic have ...

Homework Statement In the figure shown below, a light ray enters a glass slab (with index of refraction nglass = 1.65 ) at point A and then undergoes total internal reflection at point B. The medium that surrounds the glass slab is a liquid whose index of refraction, nliquid =...

Homework Statement a battery with unknown internal resistance and open circuit potential (emf) is connected toa 3 ohm external resistor. the terminal potential is found to be 60 volts. when the same battery is connected to a 48 ohm resistor, the terminal potential is 96 volts. what is the...

http://img210.imageshack.us/img210/6094/questionuz8.png i) What is the angle of refraction of the ray RS after it strikes the glass prism of refractive index=1.5? ii) If the critical angle is 41.8 degrees, deduce whether the ray will suffer total internal reflection. 2. Homework Equations ...

This is a rather interesting development and it will be interesting to see where it goes. I guess this is good news? Al-Qaida at War with Itself, Author Says http://www.npr.org/templates/story/story.php?storyId=90805085 Seems like there is an opportunity to reduce terrorism if groups like...

[SOLVED] Internal energy of a gas Is the internal energy of a gas simply the total kinetic energy possesed by the particles? I ask this, since I have read this to be the case, however I have also read that when changing state, eg. from liquid to gas, the latent heat is the energy required to...

The battery of an electric car consists of 30 cells, connected in series, to supply current to the motor. (a) Assume that the internal resistance of each cell is negligible and that the pd across each cell is 6.0V. (i) State the pd across the motor. (ii) The battery provides 7.2kW to the...