Internal Definition and 993 Threads

I am having trouble with a homework problem assigned by my physics professor. An infinitely long cylinder of radius a and relative dielectric constant Er is immersed in a static electric field E=Eox where x is supposed to denote a unit vector in the x direction. The cylinder is alligned on the...

Homework Statement A cell is connected to a 10.0 Ohm resistor. The pd across the 10.0 Ohm resistor is 10.43 V. A 4.00 Ohm resistor is connected in parallel with the 10.0 Ohm resistor. The pd across the 10.0 Ohm resistor falls to 7.87 V. Calculate the emf and the internal resistance of the...

The law says that the maximum thermal efficiency of a heat engine can be 88%. If I have and internal combustion engine using 9.8 cc/min instead of 25 to 30 cc/min and the other accepted figure is a 2L 4 cylinder engine for idle is it uses approx 5 HP of fuel just just to idle. So I am doing...

Homework Statement See figure attached for problem statement. Homework Equations The Attempt at a Solution Using Snell's Law, n_{1}sin(\theta_{1}) = n_{2}sin(\theta_{2}) n_{1} = \frac{n_{2}sin(\theta_{2})}{sin(\theta_{1})} Where, \theta_{1} = 30^{o}, \theta_{2} =...

If we melt ice at 0'C to water at 0C, what is the change in the internal energy of the ice-water system? As per the first law of thermodynamics, ΔU = ΔQ +ΔW where they are increase in internal energy, heat flow to the system and work done on the system respectively. If we melt ice at 0C, we...

I'm not entirely sure if this is meant to be in the "advanced physics" section, it's for my undergraduate degree anyway. Homework Statement A conducting sphere of radius R, carries a total charge of q. It is surrounded by an electrically neutral conducting shell with an inner radius, a, and...

Homework Statement There's a slab of a material with temperature T1 on the left and the T2 on the right. The thickness of the material is l with area A. In the centre, there is heat generation Qvol in the centre, which is a thin rod. Find the heat transfer Q through the material. Homework...

What is the "driving force" to increasing the internal resistance of a battery Homework Statement A brand new battery almost have no resistance, but overtime when the internal resistance is great enough, the battery "dies". So my question is, what is causing the internal resistance to...

In thermodynamics Change in Internal Energy = Heat - Work (\DeltaU=Q-W) During vaporization my Heat is mass*Latent Heat (Q=mL) and Work is Pressure*change in volume (W=P\DeltaV), so \DeltaU=mL-P\DeltaV. Let's take any of the natural monoatomic gases, Neon in this case. \Delta = Volume...

Homework Statement When a 60 \Omega resistor and a 120 \Omega are connected in parallel across a battery there is a current of 700 mA flowing through the battery. When the 120 Ohms resistor is disconnected from the circuit the current through the battery drops to 500 mA. What is the emf and the...

Homework Statement An emergency supply consists of a small diesel engine driving an alternator. The output of the alternator is rectified and smoothed to produce DC. This has has to supply 10 amps of 110V emergency lighting and charge a 110V battery of internal resistance 2 ohms, If the...

Homework Statement A 21 cm spectral line corresponds to the flipping of the electron in a hydrogen atom from having its spin parallel to the spin of the proton to having it anti-parallel. Find the internal magnetic field experienced by the electron in the hydrogen atom. Homework Equations...

As a practical matter, the internal energy of a system is treated as a state function of a the system and is concerned only with the kinetic energy of particles, not the potential energy. So for thermodynamic entropy, S=E/T, (S=entropy, T= absolute temperature) I'm considering E to be kinetic...

How is that in refraction of light energy is lost but not in case of total internal reflection? Is the loss in total internal reflection exactly zero?

Homework Statement [PLAIN]http://img689.imageshack.us/img689/3047/directproduct.png < denotes a subgroup. \triangleleft denotes a normal subgroup. The Attempt at a Solution Have I done (a) correctly? 0 \in A so A \neq \emptyset If a=x+ix and b=y+iy then ab^{-1} = x-y + ix...

Homework Statement Assume a star is in hydrostatic equilibrium and that the density of the star is follows \rho \propto \frac{1}{r^{a}} where \r is the distance from the centre of the star and \r is a constant. Derive an relation for the pressure of the star as a function of \r...

I have an enclosure in which the electrical components put off 10,500BTU/hr. At the top of the enclosure the internal hot air is in contact with circular aluminum tubes. Ambient outside air at 70 degrees F is blown through the center of the tubes at 500cfm. Internal hot air and outside ambient...

Homework Statement A voltmeter whose resistance is 1000 ohms measures the voltage of a worn out 1.5V battery as .9V. What is the internal Resistance Homework Equations The Attempt at a Solution In order to do this, I Solved for the Equiv Resistance of the circuit (leaving in...

For a commutative ring R and an ideal I, is it true that I \oplus R/I \cong R ? I know in some cases this is true, and I know it's true for finitely-generated Abelian groups, but is it true for any commutative ring? In other words, we know that R/I is isomorphic to some ideal in R, call this...

Homework Statement Hi I wonder if anyone can help. I am having difficulty drawing refracted and total internally reflected rays. I have an exam on Monday. Can anybody recommend good websites that can help? Slight panic. Thanks Homework Equations The Attempt at a Solution

Homework Statement A helium balloon with a volume of 1m^3 and temperature of 27 deg c is placed in liquid nitrogen in an open container and cools to a temperature of 77 K. Assume that helium behaves like an ideal gas at constant atmospheric pressure and find the new volume of the gas in the...

hello.. this is my first post..forgive me if my question is wrong.. Why does a current source is modeled in such a way that it has its internal resistance in parallel ? Why can't it have its internal resistance in series ? The question may seem awkward , but please answer me.. thanks in advance..

Homework Statement A container of volume 0.72 m^3 contains 1.4 mol of argon gas at 24 degrees C. Assuming argon behaves as an ideal gas, find the total internal energy of this gas. The value of gas constant is 8.31451 J/mol x K. Answer in units of J. Homework Equations PV=nRT...

Question about Total Internal Reflection? My textbook says that for total internal reflection to occur 2 conditions need to be met. Light is traveling more slowly in the first medium than the second medium and no.2 is the angle of incidence must be large enough for no refraction to occur. My...

Question about Total Internal Reflection? My textbook says that for total internal reflection to occur 2 conditions need to be met. Light is traveling more slowly in the first medium than the second medium and no.2 is the angle of incidence must be large enough for no refraction to occur. My...

How to calculate Energy absobed by the components of a Truck Cab after crash test?? Hi, I have a question regarding the calculation of internal energy of components after collision. In conducting the frontal impact test as per the ECE R29 regulation, a swing bob has to hit the front of...

hi, if suppose a battery is 100% charged and is capable of delivering 12V. Now if i connect a bulb of 40watts across it then their will be a voltage drop and the internal resistance can be calculated. If the same battery with 100% charge is used with a 80watts bulb then again their will be a...

Homework Statement Helium (He), a monatomic gas, fills a 0.010-m^3 container. The pressure of the gas is 6.2 multiplied by 10^5 Pa. How long would a 0.38-hp engine have to run (1 hp = 746 W) to produce an amount of energy equal to the internal energy of this gas? Homework Equations...

We known U=3/2nRT (monatomic ideal gas), just depends on temperature. Most texts assert connecting U and Q with constant volume condition and say"\Delta U = nCv\Delta T for any process because of internal energy only depends on temp". I think that statement is very strange. Deriving...

Homework Statement Two grams of water are sealed in a rigid con- tainer; then the water is vaporized by heating. 1664 cal of heat is needed for vaporization. What is the change in internal energy of the water? Answer in units of J. Homework Equations 1 kcal= 4,186 J The Attempt...

Hey people I intend to self learn IC engines. I am a a little confused by what this sentence says in my textbook. "An idling engine is one which operates at no load and with nearly closed throttle" I basically want to know what loading means in this particular context? And what else can...

Ok guys I need help! Its been a while since I last opened a physics workbook and now I'm back to studying to try and further my career and I've come across an internal resistance question that I can't get my head around! A resistance of 10.5 ohms is connected across the terminals of a battery...

hi, Can anybody explain the phenomenon behind internal energy? and what is the change in internal energy when water evaporates. Please do give reference to first law of thermodynamics. Thanks in advance.

I have the truss shown, I'm supposed to find the internal force for each of the vertical members...I understand method of joints and method of sections, but can you use both method of joints and sections in the same problem...for example I found Ly=52.5 and Ry=32.5 using moments and summing in...

Homework Statement A gas obeys the equation p(V-b) = RT and has cv independent of temperature. Show: (a) the internal energy is a function of temperature only (b) the ratio cp/cv is independent of temperature and pressure (c) the equation of an adiabatic change has the form p(V-b)^gamma...

Hi all, From what I understand, total internal reflection reflect 100% of light. Suppose you had a transparent material with a critical angle of 45 degrees. Now say you had a cone with a 45 degree angle, and you shined monochromatic light in through the base. Would 100% be reflected (minus...

Homework Statement A long narrow solid rod has an atomic density 5 \times 10^{28}m^{-3} each atom has a polarizability of 10^{-40} . Find the internal field when an axial field of 1 V/m is applied.Homework Equations im not sure what formula to use but here's one: p = E_{loc} \sum_{r} n_j...

Homework Statement please see the image, I am supposed to find the internal force in each member of the truss and state if its in compression or tension Homework Equations The Attempt at a Solution here is what I have so far (all in kN)... My=40 up Gy=80 up Mx=0 from joint G...

please see the attached image, I'm supposed to find the internal force in each member of the truss. I used moments to find My=40 and Gy=120, I then moved on to FBD of joint G where I found Fgh=30kN in tension, and Fga=50kN in compression, next I did joint A to find Fab=30kN in tension...

Homework Statement an internal explosion breaks an object, initially at rest, into two pieces, one of which has 1.5 times the mass of the other. If 7500 J were released in the explosion, how much kinetic energy did each piece acquire. Homework Equations K1+K2=7500J...

Homework Statement an internal explosion breaks an object, initially at rest, into two pieces, one of which has 1.5 times the mass of the other. If 7500 J were released in the explosion, how much kinetic energy did each piece acquire. Homework Equations mgyi+1/2mvi2=mgyf+1/2mvf2 The...

Homework Statement Julie has a mass of 60 kg. In an experiment she crouched down, then jumped straight up. Her lab partners measured the height of her center of mass above the floor at three instants: 1) 0.43 m when crouched down; 2) 1.02 m just as her feet were leaving the floor; 3) the...

Problem: Given a circle of radius 1. Take a sector of this circle with internal angle A, where 0=<A=<pi/2. Find a formula for the radius of the smallest circle that will perfectly fit this sector, as a function of A. Solution. I used laws of sine and cosine and came up with...

Homework Statement Show that internal energy U = U(T) only for an ideal gas who'se equation of state is: P(V-b) = RT (the claussius equation for n moles of gas) Homework Equations Thermodynamic Equation of state: \left(\frac{\partial U}{\partial V}\right)_T =...

Homework Statement For Cyclohexane Boiling point T_b = 80.1°C P = 1atm \Delta H_{vap} = 30.1 kJ/mol Determine at phase change liquid to vapour, Changes in: a)Entropy per mole b)Gibbs free energy per mole c)Internal energy per mole assume ideal gas behaviour for the vapour...

Hi, I had a question about Torque, Internal forces & external forces. Here are 2 examples helping me to state my question: 1) The Earth is rounding the sun with respect to the Sun. The forces which are acting on the system are 2 gravitational forces that are action & re-action. The Force...

Why is internal energy not sufficient to compare states? Thank you for your answer.

A book listed the problem infinite circular cavity under internal pressure and said there is a analytical solution for stress and displacements but it didn't give any reference. I have searched many papers and online materials but still couldn't find anything. The closest thing I found...

Homework Statement http://img694.imageshack.us/img694/9990/fig24a.jpg" The scenario is, the water in the beaker = system 1. Everything else, including walls = system 2. The bunsen burner heats the water in the beaker. dU or the change in internal energy of system 2 decreases. dT or the...

Hi! I'm trying to fully grasp why the potential drops when an internal resistance is present in a source of emf. At first I thought that yes it would be harder to "push" the charges to the higher potential, but once there, why shouldn't the higher potential be the same as before? Just as if a...