Internal Definition and 957 Threads

"What is the internal energy of 10 moles of helium at 100 K?" The same question is asked about 10 moles of oxygen. I'm going to guess PV=nRT which would give 8,314 J as the PV value. Because (at least in chemistry this is true) delta H = delat E +/- work and work = PV, so PV would somehow...

I am given that a DE with the form x' = f(x) is defined on the interval (c,b) where f has continuous derivative on its domain How do i show that if f(p) = f(q) = 0 and x(t) is between p and q then the maximal interval of existence of x is (-∞, ∞)

Homework Statement Two speeding lead bullets, one of mass 15.0 g moving to the right at 270 m/s and one of mass 7.65 g moving to the left at 390 m/s, collide head-on, and all the material sticks together. Both bullets are originally at temperature 30.0°C. Assume the change in kinetic energy of...

could anyone explain me the fundamental different between internal energy and enthalpy? I searched and found the below definitions for both terms. INTERNAL ENERGY:In thermodynamics, the internal energy is the energy contained by a thermodynamic system. ENTHALPY:Enthalpy is a measure of the...

Hi, When we have total internal reflection of light at the boundary of an optically dense to an optically thinner medium, one can show that the component of the Poynting vector perpendicular to the boundary is zero, i.e. there is no energy flow into the thinner medium. However, the electrical...

My high school teacher told me that internal forces of a system do not change the Centre of Gravity of a system. I have doubt regarding this. If internal force is applied to the wall of a system, the CG must change right? If not, where'll be the result of applied force. I have some examples...

We say that spin is an intrinsic angular momentum which does not have anything to do with space. But is it possible that it is the orbital angular momentum of some internal constituent particles (a yet unknown fine structure)?

Hello, ##E_{tot}^2=(pc)^2+(m_0 c^2)^2## works fine for mass ##m_0## moving with relativistic speeds. What if the moving mass has internal energy also (say, heat). Does the energy-momentum relation still apply? What is the expression for the momentum ##p## then? Because ##p=\gamma m_0 v##...

Homework Statement A cell of unknown e.m.f. , ε , and internal resistance, r, is connected in series with a variable resistor. A voltmeter is then connected across the terminals of the resistor. When the resistor has a value of 16.0 Ω the voltmeter reads 1.20 V. When the resistance is...

Homework Statement A circuit is constructed with five resistors and one real battery as shown above right. We model. The real battery as an ideal emf V = 12 V in series with an internal resistance r as shown above left. The values for the resistors are: R1 = R3 = 59 Ω, R4 = R5 = 79 Ω and R2 =...

Homework Statement Does a flashlight battery have internal resistance? Explain. Homework Equations V = ε - Ir The Attempt at a Solution Yes, they do have internal resistance. This results in the open circuit ε being different than the voltage measured across the terminals if a current is...

Homework Statement When a 10 ohm load is placed across the terminals of a battery, the terminal voltage is 11.0V. When a 100 ohm load is used instead, the terminal voltage is 11.9V. What is the internal resistance of the battery? Homework Equations V=IR The Attempt at a Solution...

Then I see this line in a Wiki article: For an ideal gas, the heat capacity is constant with temperature. Accordingly we can express the enthalpy as H = n C_P T and the internal energy as U = n C_V T, where n is the amount of substance in moles. Thus, it can also be said that the heat...

Hi all, During steady state cornering which tire of the same axle experiences the higher side force? I believe the external one for higher normal load due to the weight lateral transfer. Is it true?

Imagine a square prism made from some material with such an index of refraction and surrounded by a substance of such index of refraction so that light rays entering the prism and hitting one of the internal sides of the prism at an angle of incidence 45° experience total internal reflection...

Homework Statement The internal energy of a gas is 597 joules. The gas is compressed adiabatically and its volume decreases by 129 cm3. If the pressure applied on the gas during compression is 3.43 atm, what is the internal energy of the gas after adiabatic compression? Homework Equations...

Homework Statement The internal energy of a system is expressed by function U(S.V)=S4/3Vα, where α is a constant. The value of α is? The Attempt at a Solution Here internal energy is expressed in terms of volume and entropy but all the relations (as far as I know) are in terms of...

Wikipedia says its the TOTAL energy contained by a thermodynamic system. But the textbook says Total energy = internal energy + kinetic energy + potential energy

Homework Statement What internal pressure (in the absence of an external pressure) can be sustained a)by a glass tube b)by a glass spherical flask if in both cases the wall thickness is ##\Delta r## and the radius of the tube and the flask equals ##r##? (##\sigma_m## is the glass...

Hello everybody, I am working on the whole vehicle calculations, engine, brakes, suspension and engine simulation, using that software, take a look: http://www.speed-wiz.com/calculations/engine-simulation/engine-simulation-conditions.htm That software, you input the values at the top...

Homework Statement Heat flows into an ideal gas at a constant volume. The pressure increases from 1.5 atm to 5.5 atm. Next the gas is compressed at constant pressure from 5.0 L to 2.5 L and goes back to its original temperature. 1.What is the total work done on the gas in the process...

Homework Statement I have a 6 meter long beam that is supported by a roller at 0m and a pin at 6m. There is a triangular distributed load that begins at 0m to 3m which is 2kN/m. (Max load is at 0m) There is an additional triangular distributed load that begin at 3m which mirrors the first...

I got this question ( i won't include a lot of details because this is not the homework forum) where i need to calculate the power dissipation due to internal resistance. What i did is , i calculated total V and total R and I , then i treated the battery as a normal resistance ( eg. a 1kohm...

Homework Statement I have a 13 foot long beam supported by a pin at x = 0 feet and a roller at x = 9 feet. There is a triangular distributed load of 50 lb/ft from 0 ft to 9 ft. (Increasing as it approaches 9 ft) At the end of the beam there is a moment of 200 lb-ft counter-clockwise.Homework...

Homework Statement 400. g of oxygen has a volume of .25 m3 and a pressure of 125,000 Pa. What is the internal energy of the gas? What would the internal energy of the gas be if it were compressed to .10 m3 while the pressure was held constant?Homework Equations U = 3/2 PVThe Attempt at a...

Hi everyone, I have attached an image of the op-amp configuration (all op-amps are ideal). Basically, the question asks to calculate the resistance seen through the voltage source. The answer is 3 kΩ but I just don't understand how this is found. If someone could assist me, I would really...

Lead Acid Battery "Internal Resistance" and Temperature Hello, I've reached my wit's end trying to understand the theory behind charging lead-acid batteries. I believe I have read over twenty different articles, maybe six hours worth of studying. According to what I've read: Charging...

I'm having some trouble with my majors for college as an incoming freshmen. I love physics as a course, conceptually. However, mathematics has always been a subject of terror for me, leaving me destitute in the department of understanding. But as interested as I am, I'm willing to force myself...

Homework Statement http://postimg.org/image/4lvunjeoz/ Solution: http://postimg.org/image/v1d7gilef/ When you have to calculate the internal forces at a point, how do you decide which forces are included in the free body diagram? For D, why isn't the rectangular bit of the distributed load...

Homework Statement http://postimg.org/image/i1r51jolz/ The Attempt at a Solution can someone help me determine the internal forces I need to work out the stresses for part A? http://postimg.org/image/c2uv3fwmt/ I can't really get any forces from the diagram I drew?

I've got a few issues with the topic of thermodynamic expansion, ΔU, etc. With ΔU=q+w, this w is to mean work done on the system (positive contribution to ΔU) minus work done by the system (i.e. negative contribution to internal energy), so then how do we summarize this for cases of...

i wanted to know if the flow in the exhaust pipe of an ic engine cross the sonic speed? i have been seeing a lot of papers presented about the supersonic internal flows on the net and hence i wanted to know some of the practical situations where such flows can be seen?

Homework Statement Red light is incident in air on a 30o - 60o - 90 o prism as shown. The incident beam is directed at an angle of φ1 = 37.6o with respect to the horizontal and enters the prism at a height h = 26 cm above the base. The beam leaves the prism to the air at a distance d =...

Homework Statement This problem concerns a collision experiment performed on a frictionless surface with gliders A and B, with masses m(a) and m(b) respectively. In a level track, glider B has a spring-loaded plunger attached to it. At time t(i), glider A moves to the right with speed...

Homework Statement In exercising, a weight lifter loses 0.150 kg of water through evaporation, the heat required to evaporate the water coming from the weight lifter's body. The work done in lifting weights is 1.40x105 J. (a) Assuming that the latent heat of vapourisation of perspiration is...

Consider snell's law n_1 \sin{\theta_1}=n_2 \sin{\theta_2} ( n_1 and n_2 are real). We know that if n_2<n_1 , there exists an incident angle called critical angle that gives a refraction angle of ninety degrees i.e. \sin{\theta_c}=\frac{n_2}{n_1} . But if the incident angle is greater...

Hi all, I was taught that internal energy of an ideal gas in depending on the temperature which mean during isothermal process, the change in internal energy is equal to zero. Is this statement true? How about the change in the internal energy of a substance when it is condensed from...

Homework Statement I know the area of a right angled triangle, I also know the ratio of the two non-hypotenuse sides. Is there anyway of finding the lengths? Thanks! Homework Equations I don't think there are any like Area = 1/2abSinC The Attempt at a Solution I obviously...

Homework Statement Internal moments need to equal external moments, work out the total of the internal moments. The object has a mass of 2 kg Homework Equations I have obtained the moment about I (labelled as MI) + Iα The Attempt at a Solution the moment about I (MI)...

gauge forces like electromagnetic, weak and strong forces have local gauge symmetry invariance in terms of u(1), su(2), su(3) because the em for example can't have the same global phase or global symmetry at all points of space. but is there no corresponding gauge forces for global symmetry?

And I mean the angle with the normal vector. Suppose you shine a laser through a prism at a large angle of incidence, and the prism has index of refraction 1.7. You get the angle of incidence high enough, and you get total internal reflection. Then you put a 1/4 wavelength layer of MgF, index...

Hi And Need Help The main Question is what happens to light and cause go into next medium as total internal reflection happens for incident angles higher than critical angle ? so the main question is why the light path throughout the second medium? We know when light travels from a medium...

Hello, Please i have a question about the internal energy: The Internal Kinetic energy is the motion of molecules and it's a random motion. But at macroscopic level the whole object formed by those molecules move in a same direction? how it can be? In a flowing fluid not static? thank you

Hello, I do not understand how to know where to ''cut'' the sections when finding internal forces in a structure, for example why they cut it into 3 sections at the locations the textbook did in figure 9.17. Thank you

internal energy U=q+W so far we've only been substituting -PV into W but i just wanted to be sure that the W is the total work and not just the work done by the pressure right?

Hello everybody. The concept of internal energy of a real vs ideal gas has perplexed me. From what I understand, an ideal gas solely considers the kinetic energy of gas molecules (temperature) where as real gases consider kinetic energy of particles in addition to potential energy. So...

Homework Statement An optical fiber consists of a glass core (index of refraction n1) surrounded by a coating (index of refration n2<n1). Suppose a beam of light enters the fiber from air at an angle θ with the fiber axis as shown in attached. (a) Show that the greatest possible value of θ...

Homework Statement Two closed containers A and B contain equal number of moles of ideal gases GD (diatomic)and GM (Monoatomic) ,respectively. Q .1 a) If the temperature of gases are same,which of them has more average translational kinetic energy ? b) Which of them has more...

Change in internal energy at constant pressure?? Hello everybody, I am stuck with a concept in thermodynamics. We know that ΔU=CvΔT. But what if we want the change in internal energy at constant pressure? ΔU→Change in internal Cv=heat capacity at constant volume

i am calculating the properties of an internal combustion engine, however, for efficiency i am getting a value of 0.2%.This seems too low to be correct. please see attached table of values and point out any figures that seem incorrect thanks