Carnot Definition and 277 Threads

Homework Statement A Carnot air conditioner takes energy from the thermal energy of a room at 70 degrees F and transfers it to the outdoors, which is at 96 degrees F. For each joule of electric energy required to operate the air conditioner, how many joules are removed from the room? Homework...

Homework Statement A steam engine has a cylinder 80cm in diameter with a piston that has a total travel length of 1.8m. Assume that there is no "dead space" between the cylinder head and the piston when the piston is farthest in the cylinder. Steam is piped into the cylinder head from an...

Suppose an engine uses multiple heat reservoirs: When calculating the carnot (maximum possible efficiency) is it valid to simply take the average of the temperatures of the hot reservoirs from which the heat is extracted as T(hot) and the average of the temperatures of the heat sinks to which...

Homework Statement This is from "Equilibrium Statistical Physics" by Plischke and Bergerson, problem 1.1: "Consider a Carnot engine working between reservoirs at temperatures T1 and T2. The working substance is an ideal gas obeying the equation of state [ PV=Nk_BT ], which may be taken to be...

Homework Statement A Carnot Engine operating between 900 Fahrenheit and 90 Fahrenheit produces 40,000 ft-lb of work. Determine (a) the heat supplied, (b) the change in entropy during heat rejection and (c) the thermal efficiency of engine. (answers should be in BTU) Homework Equations What...

the carnot engine does not obey any law of thermodynamics,because it has 100% efficiency,now do we have any engine that has come close to this hypothetical engine?(in terms of efficiency ) can this process of carnot be used for a 6 stroke engine?(hypothetically)

Hey. I'm supposed to calculate the work done in an adiabatic process, B-C, and I only know the values of the temperatures and the volume in the first point (point B). It is not known if it is a mono or diatomic gas, therefore i don't know the value of gamma. I've tried T*V^(gamma-1)=K and the...

quick question, is the difference between a carnot engine to an engine is that the engines eff is less than or equal 1-(cold temp / hot temp), and the carnot is the max of this which is just equal 1-(cold temp / hot temp)?

Homework Statement An ideal Carnot engine produces a power output of 5kW at a thermal efficiency of 35% while rejecting heat reversibly to a reservoir at 30degrees. It achieves this output while executing 10 cycles per second. a) What temperature is the engine receiving its heat supply...

[b]1. The efficiency of a cyclic engine is given by the work done by the engine, divided by the heat intake from the surroundings. One Carnot engine drives another in series. Draw a schematic diagram of the combined engine and give an expression for the overall efficiency of this arrangement...

A Carnot heat engine uses a hot reservoir consisting of a large amount of boiling water and a cold reservoir consisting of a large tub of ice and water. In 5 minutes of operation of the engine, the heat rejected by the engine melts a mass of ice equal to 2.85×10−2 Kg. Throughout this...

Homework Statement A Carnot engine using a gas operates between 2 reservoirs of temperatures 1000K and 280K. The work output per cycle is 1kJ. a) What is the efficiency? b) What is the entropy change of the gas per cycle due to the heat transfer at the hot reservoir? Homework Equations...

Homework Statement A Carnot freezer in a kitchen has constant temperature of 260k, while the air in the kitchen has a constant temperature of 300K. Suppose the insulation for the freezer is not perfect and energy is conducted into the freezer at a rate of .15 Watts. Determine the average...

A carnot engine uses 0.05kg of air as the working substance. The temperature limits of the cycle are 300K and 940K, the maximum pressure is 8400KPa, and the heat added per cycle is 4.2KJ. Determine the pressure and volume at each state of the cycle. r(gamma)=1.4 and R=0.287KJ/Kg Kim pretty sure...

i want to ask why heat transfer is considered ti be an irreversibility and why in carnot carnot cycle heat addititon is at constant temperature to make this process reversible

Homework Statement An ice making plant consists of a reversed Carnot engine extracting heat from a well- insulated box. The temperature in the icebox is -5C and the temperature of ambient air is 30C. Water of an initial temp 30C is placed in the icebox and allowed to freeze and cool to -5C...

Homework Statement From the hot reservoir at a temperature of T1, Carnot Engine A takes an input heat of 5550J, delivers 1750J of work and rejects heat to a cold reservoir that has a temperature of 503K. This cold reservoir also serves as the hot reservoir for a second Carnot Engine, B, which...

Homework Statement In one location, the average daily temperature varies sinusoidally between 35C in summer and 0C in winter. The ground temperature below 2 m underground is the annual average temperature. A heat pump / air conditioner unit must deliver air to a house at 30C in winter and...

In the textbook, it reads: the reverse of carnot cycle is just a refrigerator or heat pump. In this sense, except for the direction of carnot cycle is reverse, could I say the way to calculate the efficiency of the carnot refrigerator is the same? That is, could be still use \eta = 1 -...

Something > Carnot efficiency ? WTF? So I've made a very simple, ideal model of a heat engine, and my calculations just don't match up to the carnot thing: efficiency = 1-(Tc/Th) It looks like this: I supposed a rectangular block, base of 1cm by 1cm, and a piston free to move up and down...

Homework Statement An ideal (Carnot) engine has an efficiency of 50 % If it were possible to run it backward as a heat pump, what would be its coefficient of performance? Homework Equations COP = (TL) / (TH - TL ) The Attempt at a Solution no temperatures are given. I just...

I was wondering if anyone would be able to help with this question; Two carnot engines operate in series between a source 800K and a sink of 290K. The first engine rejects 400kJ to the second engine. If both engines have the same efficiency, calculate; (i) the temperature for the source of...

Homework Statement A heat engine operates in a Carnot cycle between 80 degrees C and 350 degrees C. It absorbs 21,000 J of energy per cycle from the hot reservoir. a. THe duration of each cycle is 1s. What is the mechanical power output of the engine? b. How much energy does it expel in each...

Homework Statement The exhaust temperature of a Carnot heat engine is 121◦C. What is the intake temperature if the efficiency of the engine is 13.4 %? Answer in units of ◦C. Homework Equations e=1-(Tc/Th) The Attempt at a Solution This seems like just a plug and chug problem...

Homework Statement I am not necessarily having a problem with a particular homework problem. It is more of a conceptual issue. I have been reading about Carnot engines and refrigerators. In trying to understand the topic better, I did a little more digging and looked up how a refrigerator...

A firebox is at 750K, and the ambient temperature is 300K. The efficiency of a Carnot engine doing 150J of work as it transports energy between these constant-temperature baths is 60.0%. The Carnot engine must take in energy 150J/.600 = 250J from the hot reservoir and must put out 100J of...

Homework Statement An ideal Carnot engine takes in 160 kcal of heat at 110°C and exhausts some of this at 10°C. How much work (in joules) must have been done by the engine? Homework Equations The engine's efficiency is ε = (TH - TL)/TH. The hint tells me that I need to use the First Law of...

Homework Statement an ideal gas operates in a carnot cycle so that it produces a net positive work of 400 joules per cycle. the maximum temperature during the cycle is 300 deg celsius and the heat lost to a low temperature bath is 600 joules per cycle. a) what must be the temperature of the...

A Carnot heat engine uses a hot reservoir consisting of a large amount of boiling water and a cold reservoir consisting of a large tub of ice and water. In 5 minutes of operation of the engine, the heat rejected by the engine melts a mass of ice equal to 3.40×10^−2 kg. Throughout this problem...

An ice-making machine inside a refrigerator operates in a Carnot cycle. It takes heat from liquid water at 0.0 C and rejects heat to a room at a temperature of 22.2 C. Suppose that liquid water with a mass of 86.2 kg at 0.0 C is converted to ice at the same temperature. Take the heat of fusion...

Homework Statement Which of the following statements about a Carnot engine is true? a) Any Carnot engine has an efficiency of 100% b) Irreversible energies have the greatest possible efficiency. c) Heat can spontaneously flow from a cold reservoir to a hotter reservoir. d) If a process is...

Homework Statement A heat pump is used to heat a building. The outside temp is -5.0 Celsius and the temp inside the building is to be maintained at 22 Celsius. The pump's coefficient of performance is 3.8, and the heat pump delivers 7.54MJ as heat to the building each hour. If the heat pump...

[SOLVED] Carnot engine - please help asp I just typed a whole question and as I typed it I solved it, lol! Homework Statement In the 1st stage of a 2-stage Carnot engine, energy is absorbed as heat Q1 at temp T1, work W1 is done, and energy is expelled as heat Q2 at lower temp T2. The...

I have a question on Why the Carnot cycle is not used with real engines? I need to refer to real cycles in my explanation.

[SOLVED] Heat Engines and the Carnot Cycle Homework Statement The operating temperatures for a Carnot engine are Tc and Th= Tc + 55K. The efficiency of the engine is 15%. How do i find Tc?

Homework Statement Homework Equations You are designing a steam engine and you want to make it as efficient as possible in terms of the energy used to run it and the useful energy it can produce. What do you want to maximize and minimize in terms of the steam temperature and the...

Homework Statement A Carnot heat engine uses a hot reservoir consisting of a large amount of boiling water and a cold reservoir consisting of a large tub of ice and water. In 5 minutes of operation of the engine, the heat rejected by the engine melts a mass of ice equal to 3.50×10−2 kg ...

1. Homework Statement 1) A 200 litre container of boiling water and a 200 litre 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 water...

I have two short questions: 1) Is the Carnot cycle completely reversible? 2) \Delta S = 0 for a reversible process, right?

Homework Statement An ice-making machine inside a refrigerator operates in a Carnot cycle. It takes heat from liquid water at 0.0C and rejects heat to a room at a temperature of 25.0C. Suppose that liquid water with a mass of 78.3kg at 0.0C is converted to ice at the same temperature...

Homework Statement We have stressed that the Carnot engine does not exist in real life: It is a purely theoretical device, useful for understanding the limitations of heat engines. Real engines never operate on the Carnot cycle; their efficiency is hence lower than that of the Carnot engine...

Is it possible to show that the maximum efficiency for a heat engine is given by \eta = 1 - \frac{T_c}{T_h} where T_c is the temperature of the cold sink and T_c is the temperature of the warm sink? In other words: How do I prove that a engine run by a Carnot cycle is the most efficient engine?

i have this example problem...and i want to know how to answer this problem :confused: a carnot engine is operated with its maximum temperature equal to 700K and 300kW were rejected. what is the sink temperature, if 450kW enters at the upper temperature. tanx for your help..

hi i just want to know the formula of the otto cycle for the folowwing parameter: compression ratio,cycle work,heat added,heat rejection,thermal efficiency and mean effective pressure. and also may i know the formula for getting the pressure (bar) and the volume(m3/kg) temperature(K) for...

Hi, I need some help concerning the Carnot cycle [i've searched, but what i needed didn't come up]. I am trying to work out the efficiency of a 4 or 2 stroke motorcyle engine. [car engine, it doesn't matter really]. But I'm having some difficulty finding temperatures for the hot and cold...

I would like to ask anybody who can help me to find some notes on the Carnot Cycle and the 2nd law of thermodynamics. What is it about. thanks

Homework Statement There are two Carnot engines in series, so that the heat exhaust from the first engine drives the second. Find the overall efficiency of the arrangement which contains only the efficiences of the individual engines. Homework Equations \epsilon = \frac{W}{Q_{input}}...

The inside of an ideal refrigerator is at a temperature , while the heating coils on the back of the refrigerator are at a temperature . Owing to a malfunctioning switch, the light bulb within the refrigerator remains on when the the door is closed. The power of the light bulb is ; assume that...

Homework Statement Under many conditions, the rate at which heat enters as air conditioned building on a hot summer day is proportional to the difference in the temperature between the inside and outside, Th-Tc. (If the heat enters entirley by conduction,this statement will certainly be...

Halliday says that the efficiency of an ideal Stirling engine is lower than that of a ideal Carnot engine?? But why?? It seems to me that there efficiency are both \epsilon =1-\frac{T_L}{T_H} Though Halldiay also say that this equation do not apply to Stirning engine but only to Carnot...