Carnot Definition and 292 Threads

Please i need answer for this questions A- compare the Carnot cycle with the Ranking Cycle B- State The Steady Flow Energy equation and discuss the Origin and definition of each of the terms c- A vapour compression refrigeration using ammonia works at a condenser temperature of 40C and...

1. Please help with the following question. Given: A Heat engine goes through a Carnot Cycle as the following states: State 2 to 3: air compresses adiabatically (pressure increasing) State 3 to 4: air expanded under isobaric process State 4 to 1: air goes under adiabatic expansion process...

what is the graph of carnot cycle in P-V plane using black body radiation? given the internal energy U=aVT^4 where a is the stefan's constant and P=(1/3)aT^4. thank you

Is it true that for a Carnot cycle, the entropy change for the whole system (engine plus the two reservoirs) would add up to zero? I am reasoning that it would, by the Clausius theorem that for a reversible cycle (which a Carnot cycle is), the entropy change is zero. Otherwise it would not be...

Hi From http://en.wikipedia.org/wiki/Carnot_cycle "Reversible isothermal expansion of the gas at the "hot" temperature, TH (isothermal heat addition). During this step the expanding gas makes the piston work on the surroundings. The gas expansion is propelled by absorption of quantity Q1 of...

Homework Statement 8. A house is cooled by an air conditioner. The outside temperature is 32°C and the inside temperature is 21°C. The heat leakage into the house is 9000 kcal/hr. If the air conditioner has the efficiency of a Carnot engine, what is the mechanical power required to keep the...

All reversible cyclic processes (engines) have the same efficiency: 1-T2/T1. And Carnot demostrated this efficiency with the Carnot Cycle and went on to use this to demonstrate that this was the upper limit for efficiency. My question is, why is it that there is such importance placed on...

Please help with the following: Prove that the efficiency of two carnot engines operating in tandem, one going from a cold reservoir of temperature Tc to a hot reservoir of Ti, then the second going from a cold reservoir of temperature Ti, to a hot reservoir of temperature Th must be less than...

Homework Statement I have to draw a temperature versus entropy for a carnot engine. My solutions say that as a parallel to the PV diagram, the adiabatics on the TS diagram are vertical, going from t2 to t1 and vise versa. My question is really how an adiabatic change results in a temperature...

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...

A carnot engine has an efficiency of 59% and performs 2.5x104 J of work in each cycle. a) how much heat does the engine extract from its heat source in each cycle? b) suppose the engine exhausts heat at room temp (20oC) what is the temperature of the heat source? I know that the...

Homework Statement 433J of heat is extracted from a massive object at 0\circC while rejecting heat to a hot reservoir at 19\circC. What minimum amount of work will accomplish this? Answer in units of J. Homework Equations COP= Qc/(Qh-Qc) = Tc/(Th-Tc) The Attempt at a Solution...

Homework Statement A heat engine operates in a Carnot cycle between 75.0°C and 353°C. It absorbs 21000 J of energy per cycle from the hot reservoir. The duration of each cycle is 2.00 s. Homework Equations W=Qc-Qh, W=-P change in temperature The Attempt at a Solution I attempted to...

A Carnot engine uses hot and cold reservoirs that have temperatures of 1684 and 842 K, respectively. The input heat for this engine is |QH|. The work delivered by the engine is used to operate a Carnot heat pump. The pump removes heat from the 842-K reservoir and puts it into a hot reservoir at...

A Carnot engine uses hot and cold reservoirs that have temperatures of 1684 and 842 K, respectively. The input heat for this engine is |QH|. The work delivered by the engine is used to operate a Carnot heat pump. The pump removes heat from the 842-K reservoir and puts it into a hot reservoir...

We have a carnot engine with Th = 800 degrees Celsius, and Tc = 50 degrees Celsius. This produces a work which is drives a carnot heat pump which has heat reservoirs at Th' = 50 degrees celsius and Tc' = 0 degress Celsius. What is the ratio of heat absorbed by the Heat Engine to the heat...

Homework Statement Dear All, I have a question regarding the Carnot Cycle: (The image is taken from Wikipedia, I hope that is not a problem... In case it is I will change it.) Points one to two are an isothermal reaction. The gas, kept at constant temperature, is expanding, the...

Homework Statement You want to boil a pot of water at 20C by heating it to 100C. I suggest a way of heating the pot in a reversible manner: simply inserting a Carnot engine between the reservoir (at 100C) and the pot. The Carnot engine operates between two temperatures, absorbing heat dQ_1...

Homework Statement A possible ideal gas cycle operates as follows: (i) From an initial state (p_1,V_1), the gas is cooled at constant pressure to (p_1,V_2); (ii) the gas is heated at constant volume to (p_2,V_2); (iii) the gas expands adiabatically back to (p_1,V_1). Assuming...

Homework Statement I don't understand the process between the points in a carnot cycle. Homework Equations Can someone please explain what is going on from point to point in terms of Q (heat), U(thermal energy), and Work? The Attempt at a Solution

Homework Statement What is the relationship between the heat absorbed and rejected by the reservoirs and their temperature. If a heat pump is used to transfer heat what is the rate at which heat is added to the hot reservoir in terms of the temperatures of the reservoir and the work done by...

Homework Statement (a.) For an Ideal Gas Carnot engine, what is the relationship between heat absorbed and rejected by the reservoirs and their temperature? If a heat pump is used to transfer this heat, what is the rate at which heat is added to the hot reservoir in terms of the temperatures of...

Homework Statement Three kilograms of liquid water at 0° C is put into the freezer compartment of a Carnot refrigerator. The temperature of the compartment is -13.5° C, and the temperature of the kitchen is 24.5° C. If the cost of electrical energy is ten cents per kilowatt · hour, how much...

Homework Statement 1. A heat engine operating between 200°C and 80.0°C achieves 20.0% of the maximum possible efficiency. What energy input will enable the engine to perform 10.0 kJ of work? Homework Equations e =1- Tc/Th W=e*Qh The Attempt at a Solution I got the answer but I...

Hi All, My textbook mentions that the coefficient of refrigeration for a Carnot refrigerator acting between a hot reservoir T_{H} and a cold reservoir T_{C} is K_{Carnot} = \frac{T_C}{T_H - T_C} This got me wondering - Suppose you had 1 kg of ice at it's melting point, and 1 kg of water...

Problem / Question 1)Study the engine cycles for the Otto cycle, Diesel cycle, the Carnot cycle and the standard air cycle. Explain the principles of how they work why they are different and the benefits and disadvantages of each of the systems. I have wrote about the otto cycle...

Homework Statement A 200 litre container of boiling water and a 200 litre container of ice cold water are used as heat source and sink for a Carnot engine. Calculate the maximum amount of useful work that can be obtained from the system and the final temperature of the two containers of...

Homework Statement Determine which gives the higher efficiency of a Carnot engine, increasing the temperature of the hot reservoir, or decreasing the temperature of the cold reservoir by the same amount. Justify your answer carefully. Homework Equations (TH-TC)/TH)The Attempt at a Solution By...

Homework Statement can you please help me solve this problem? A carnot refrigerator takes heat from water @ 0 degrees celsius and rejects heat to a room at 27 degrees celsius. If 50 kg of water @ 0 degrees celsius is converted to ice @ 0 degrees celsius, how much energy must be supplied...

Nevermind for now, just redid the whole thing and saw I made a stupid little mistake in computing the first volumes that messed everything else up. A Carnot engineer operating with a perfect gas between 800C and 25C has an operating pressure range between 20kPa and 6000kPa. Determine the work...

Homework Statement A house is heated by means of a carnot engine operating in reverse (Heat Pump). The outside Temperature (Tc) is 270k, and the required inside temperature (Th) is 300k. If heating the house to this temperature normally requires 10kW of electrical heating, how much power is...

Homework Statement Consider a Carnot Cycle that absorbs heat from the hot reservoir at Thw and expels to the cold reservoir at Tcw just below Th and above Tc respectively. a.) Derive an equation that relates the four temperatures. b.) Using the first and second law, write down an...

Homework Statement A Carnot refrigerator operating between -30.0 ^ C and + 20.0 ^ C extracts heat from the cold reservoir at the rate 300 J/s. What are (a) the coefficient of performance of this refrigerator, (b) the rate at which work is done on the refrigerator and (c) the rate at which heat...

Homework Statement An ideal monatomic gas is the working substance of a Carnot engine. During the isothermal expansion, the volume doubles. The ratio of the final volume to the initial volume in the adiabatic expansion is 5.7. The work output of the engine is 9x10^{5}J in each cycle. Compute...

Homework Statement I'm trying to understand how one would plot this. Homework Equations dS = dQ/T dU = dQ-dW (W is work done by the system, Q is heat absorbed by system, U is energy) For a closed cycle, dU = 0. Carnot Cycle: 1- isothermal expansion at Th 2- adiabatic expansion to Tc...

I think it is due to friction and the carnot efficiency is derived in a reversible cycle. Also,can i build just a little bit irreversible but still carnot? But if irreversible how can i draw the graph? Still smooth line?

Homework Statement A Carnot heat engine operates between temperatures Th and Tc. (a) If Th = 515 K and Tc = 363 K, what is the efficiency of the engine? 0.30 Your answer is correct. (b) What is the change in its efficiency for each degree of increase in Th above 515 K? ? K-1 (c) What...

Hello, For a reversible heat engine between temperatures T_1 and T_2, the ratio of heat going in and out the engine is \frac{Q_1}{Q_2} = \frac{T_1}{T_2} (second law). Say T_1 = 200 K and T_2 = 273 K, then heat goes from 2 to 1 and as we can see, the ratio of heat that goes in the engine is...

Homework Statement A Carnot engine performs work at the rate of 360 kW while using 720 kcal of heat per second.If the temperature of the heat source is 650 C, at what temperature is the waste heat exhausted? Homework Equations because Th,Qh,and W are given so i going to use this formula...

in a carnot cycle the gas expands adiabatically from 200 degrees to 500 degrees. what is the efficecy? and what is the entropy change of the gas during the expansion? sorry - i got the efficiency to be: 38.8% however I am unsure how to work out the entropy chance? any hints?

Is it possible (at least theoretically) to construct engine which uses Carnot cycle and two reservoirs with temperatures T_1<0<T_2 (one of them has negative temperature which is possible e.g. in case of two-state paramagnet). Such cycle would have efficiency greater then 1. (of course the...

The Attempt at a Solution For a) I imagine it is easier to control the temperature of the hot reservoir because you could use a constant heat source e.g. bunsen burner. c) melting/freezing water. d) Entropy of the environment increases and the entropy of the universe always increases...

Homework Statement A Carnot engine runs between a high temperature of 500 C and a low temperature of 50 C. The isothermal expansion (upper branch) occurs between a volume of 0.5L and 1.0L. The isothermal contraction (lower branch) occurs between 2.0L and 1.0L. There are 2 moles of gas...

Q: A Carnot air conditioner operates between an indoor temp of 20C and an outdoor temp of 39C, how much ENERGY does it need to remove 2000 J of heat from the interior of the house? A: 130J i got 121J O.o?

A Carnot air conditioner takes energy from the thermal energy of a room at 76°F and transfers it as heat to the outdoors, which is at 96°F. For each joule of electric energy required to operate the air conditioner, how many joules are removed from the room? Attempt at problem 76 + 273 = 349 96...

Homework Statement Two heat engines operating on Carnot cycles are arranged in series. The first engine A receives heat at 927 deg C and rejects heat to a reservoir at a temperature T. The second engine B receives the heat rejected by the first engine, and in turn rejects heat to a reservoir...

Homework Statement a carnot refrigerator takes heat from water at 0 degree celsius and rejects heat to a room at 27 degree celsius. if 50kg of water at 0 degree celsius is converted to ice at 0 degree celsius. how much energy must be supplied to the refrigerator? Homework Equations Sorry, i...

This is a very quick question but in the equation e=1-Q_{C}/Q_{H} do we treat both Q's as positive even though heat goes in in one case and out in the other? Or is there some detail I'm missing that would otherwise make the result less than 1.

Homework Statement A heat pump takes heat from a hot resevoir and dissipates heat to a cold one. Both resevoirs are equal mass and specific heat capacity. Show that as the heat engine does maximal work the final temp of the resevoirs = Tf = SQRT(TcTh) Homework Equations Qin = Wout +...

Homework Statement The exhaust temperature of a Carnot heat engine is 401◦ C. What is the intake temperature if the efficiency of the engine is 40.2 %? Answer in units of ◦ C. Homework Equations e = 1 - Tc/Th (all in Kelvin) The Attempt at a Solution 0.402 = 1 - Tc/ (401+273) = 1...