Internal Definition and 957 Threads

can anyone please tell me what is the gas pressure which applies on piston head just after combustion in cylinder its very urgent and necessary for me to know this please help me

Homework Statement A monatomic ideal gas expands from 1.00 meters cubed to 2.50 meters cubed at a constant pressure of 2.00 x 10^5 Pa. Find the change in the internal energy of the gas. Homework Equations \DeltaU = Q + W The Attempt at a Solution Well, I know how to find work...

In polytropic process internal energy change is=mCv(T2-T1)? why is it not mCp(T2-T1)? Why are we not taking specific heat at constant pressure?

hi everyone, i am trying to build a very high current dc to ac inverter and i can't use a 555 timer IC because they can't source or sink but a maximum of 200mA, but i have found an internal schematic of the 555 timer IC online and have been studying it to see if i can build a very high current...

Hey all, I know that it is forbidden to post homework questions here, this is a question off a past exam, so I'm hope asking this is Kosher. A question says: "For a circular pipe of 6cm diameter, what is the expected pressure drop per unit length due to frictional losses, at a Reynolds...

Homework Statement A body m1 + m2 is split into 2 part m1 and m2 by internal explosion which generate kinetic energy K. If they move in the same line after explosion, show the speed of one part relative to the other part is Square root of ( 2K(m1+m2)/m1m2) Homework Equations The...

Basically I have been given this question: A battery of unknown EMF and internal resistance is connected in series with an ammeter and a resistance box. The current was 2.0A when R= 4.0 Ohms and 1.5A when R= 6.0 Ohms. Calculate the EMF and internal resistance. I feel you may have to...

What sort of circuit would I have to set up to figure out the internal resistance of a dry cell? Also, what would i need to be measuring and doing etc, to find this internal resistance? Thanks, Jack.

Does anyone have a quick way of estimating the amount of internal pressure a sealed tube would be able to handle without failing?

\Delta U = Q - W = Q - PV (where PV is the work done BY the system). \Delta H = \Delta U + PV (where PV is work done BY the system). 1) Above I defined PV in both equations as work done BY the system. I think this must be correct to show that when P is constant we can have \Delta H = Q...

If we apply 300 kJ of heat to 2500 moles of air at constant pressure, what is the change in internal energy? So far i think I use the equation: (f/x)nkT, but I don't know how to calculate the degrees of freedom and whether I do or not, and whether or not to calculate the number of moles by...

Hi, This is not exactly homework, but I'm not sure it belongs in any other section either. I've been reading through Applied Thermodynamics for Engineering Technologists by Eastop & McConkey. In general it's pretty good I think. However, in the first few chapters, it explained that Q+W =...

Q: 20 J of heat energy is added to an ideal gas while -40J of work is done BY the same gas. The total change in internal thermal energy of the system is what? Equations I used: \DeltaEth = Heat + Work \DeltaEth = Heat - Ws This was a problem on a recent physics test I took and I said...

“mirage” is refraction phenomenon or total internal reflection phenomenon? “mirage” is refraction phenomenon or total internal reflection phenomenon?

Homework Statement A solar cell generates a potential difference of 0.10 V when a 400 ohm resistor is connected across it, and a potential difference of 0.15 V when a 900 ohm resistor is substituted. What is the internal resistance of the solar cell? Homework Equations E - ir - iR = 0...

Homework Statement A point source of light is at depth h below the surface of a large and deep lake. Show that the fraction, f, of the light energy that escapes directly form the water surface is independent of h and is given by f=0.5(1-\sqrt{1-1/n^2}) where n is the index of...

This inquiry is in relation to internal combustion engines. I am trying to figure out how to maximize the mass of air going into my engine. Because the more air that can get into the cylinder, the more power the motor can make. Now I've been researching Bernoulli's Principle and as I understand...

Homework Statement (a) In the figure shown, show that the rate at which energy is dissipated in R as thermal energy is a maximum when R = r. (b) Show that this maximum power is P = EMF2/4r. http://www.practicalphysics.org/imageLibrary/jpeg400/208.jpg The only difference between this...

Homework Statement two identical cells of emf E and internal resistance r are connected in series. a 7 ohm resistor is connected across the combination and draws a current of 0.333A. the two cells are now connected in parallel; the 7 ohm resistor now draws a current of 0.375A from the...

What is the difference between them. Even in total internal reflection not everything is reflected. I don't get it what is the big deal?

internal energy of a gas :( Hi all! I have a problem with this equation ΔU=mCvΔT, where ΔU=change in internal energy, m=mass, Cv=specific heat of air/gas at constant volume,ΔT=change in temp. Although this expression is true for all processes which can be applied to a gas e.g polytropic...

Hi, Could someone tell me please what is the scientific consensus(or some interesting theories) on why do muons decay and what is the mechanism of it? My understanding of particle decay is based on for example neutron wchich decays because a quark in it flips from down to up. But leptons, if...

2 questions that came up in a past paper. A binary tree which is both full and complete and has h levels contains a total of 2^(h-1) leaf nodes. Prove that this is the case for all h > 0. Show that with h levels the number of internal nodes is 2^(h−1) − 1 proof by induction apparently...

This is in continuation to https://www.physicsforums.com/showthread.php?t=330495 The question that initiated my doubt reads this -- " the internal resistance of an accumulator battery of emf 6V is 10 Ohm when fully discharged . as battery gets charged up , its internal resistance drops to 1...

Hi, I'm looking for a little bit of help in this matter, I'm trying to put up a general formula of the internal force/volume in a fluid in a spot, as a function of how the velocity varies locally around that spot. What I started with was a formula I found in a book called "Physics Handbook...

I know that phase changes, such as the melting of ice, occur at constant temperature. Doesn't this imply that the change in internal energy during the phase change is zero, since the temperature remains the same? I thought that in all isothermal processes this was the case, so that the First Law...

Homework Statement 1) a complete circuit consists of a 12.0 V battery with a 4.50 ohm resistor and switch. the internal resistance of the battery is 0.30 ohms when switch is open. what does the voltmeter read when placed: a. across the terminal of the battery when the switch is open b...

Does anyone have any experience with liner material for application on pipework with internal corrosion/erosion? Pipes are designed to hold water/methanol vapour Normal operating conditions for the pipes: Temperature • Average temp - 172F • Max temp - 267.1F Pressure • Average...

Does anyone have any experience with liner material for application on pipework with internal corrosion/erosion in a Methanol Regeneration System? There are issues with internal pipe corrosion in a Methanol processing systems I am dealing with. To alleviate the current high rates it has...

Homework Statement A 24 voltt supply has a terminal voltage of 20 volts when connected to a 40R Load Resistor. Calculate the internal resistance of the supply State the conditions under which maximum power will be transferred to load. Homework Equations V = E - Ir V = p.d...

A steam engine of 1kg pulls 8 cars of 1kg each. The velocity of the engine is 0m/s initially then gets up to 4m/s in a time of 4 s while moving a distance of 5.3 meters. During that time, the engine takes in 134J of heat. What is the change in internal energy? Ok so i know that: internal...

ISP can tell what my internal network ip's are? To make a long story short, I use a router, with two computers behind it, I called my ISP for technical help, and the technician there told me I use a router (which is a reason for him to not help me..). He said he sees more then one IP address...

Homework Statement A resistor has a resistance R, and a battery has an internal resistance r. When the resistor is connected across the battery, ten percent less power is dissipated in R than there would be if the battery had no internal resistance. Find the ratio r/R Homework Equations...

Homework Statement The internal energy of a monoatomic ideal gas such as neon is simply the total kinetic energy of all its atoms. What is the internal energy of 2 liters of neon at a temperature of 200 K and pressure of 0.7 atm? Homework Equations PV = nRT KE(ave) = 3/2kT U =...

Hi guys, I am hoping some one can help me out here and after some forumlas and very basic ones at that on internal ballistics. There is a heap of information out there and they tend to jump straight to the hard stuff which tends to be tough on a novice like myself. I have done a heap of...

I am sure someone wrote with great detail on the subject, but i just can't seem to find it in the forums... I want to know about the parameters influencing the performance of an IC engine...obviously, not all parameters, but those we can conviently control specifically...how is bore/stroke...

Homework Statement To find the total internal reflection. This equation should give me 1.48 as the answer but it doesn't. Can you please give me other ways to figure this out. I really need this. Homework Equations n1sin1Ө=n2sin2Ө n1 = 1 n2 =? sin1Ө = 44 degrees sin2Ө = 48 degrees...

Homework Statement I need some help on these problems, i got most of the other problems right, but these ones I am not sure what to do with. I don't even know if those are the right equations for it. Someone please help. 1. A cylinder-and-piston containing an ideal gas is placed in...

Homework Statement Suppose a terrorist bomb has exploded next to a friend and injured him by opening two small openings in his chest wall: one on the left side, one on the right side (assume that no significant internal bleeding has occured). Can you suggest, and explain, the purpose of an...

Dear Everyone I am facing the following engineering problem. I "inject" light in a flat (6.5mm) Acrylic panel at the edges of it. Due the different refractive index of the Acrylic material (1.4) and air (1) 90% of the "injected light" experiments total internal reflexion. I need to get the...

When taking internal resistance into account, voltage/current graph has negative gradient (i.e. internal resistance).? My thoughts... Because for ohmic resistors, graph has a positive gradient. Why does one say that when V=0, Current = max, whilst the other says that when V=0, Current = 0?

The name "phantom limb" implies an external extension of the body. Has a similar phenomenon been reported for internal organs? Thanks for any and all.

Homework Statement Hi everyone. I am attempting to calculate the internal moment at point B about the y-axis. I have correctly found everything else. My calculations: Weight of 500mm section of pipe = 58.9N Weight of 400mm section of pipe = 47.1N Vertical reaction at A = 58.9 + 47.1 = 106N...

Homework Statement A 5.60ohm resistor is connected to a battery that has 0.200ohm internal resistance, and a terminal voltage of the battery is 10.0V. What is the current in the resistor? What is the emf of the battery? Homework Equations EMF=terminal voltage+(I)(Rint.) V=RI The...

I'm trying to determine the forces that an internal gear applies on a pinion. I can measure the angular velocity of the gear and any relevant dimensions but can only find force equations for gears with a single point of contact. Any guidance is greatly appreciated.

Homework Statement Please help, I've been struggling with this question for so long! We haven't done internal energy so I am not sure even where to really begin? A 10.0 kg block is dragged over a rough, horizontal surface by a 76.0 N force acting at 20.0° above the horizontal. The block...

Homework Statement The prism is replaced by a new prism of the same shape, which is set in the same position. The light beam experiences total internal reflection at the right surface of this prism. What is the minimum possible index of refraction of this prism? Homework Equations...

Can i ask sth? Why centripetal accel is from an internal force? Usually what type of forces can be considered as external force, besides friction? And, for static equilibrium, do we only use the eqn: sum of forces equals zero, or we can also apply sum of moments equals zero? Thanks!

Hi, I am going to teach a class of year 9 students on the topic "Thermal Properties of Matter" and the concept of Internal Energy is mentioned inside. As I was trying to anticipate the types of questions that will be asked by them, this question suddenly struck me: Is there a limit to the...

Homework Statement Tarzan, whose mass is 110 kg, is hanging at rest from a tree limb. Then he let's go and falls to the ground. Just before he let's go, his center of mass is at a height 3.0 m above the ground and the bottom of his dangling feet are at a height 2.0 above the ground. When he...