교과서 질문
A Carnot refrigerator is operated between two heat reservoirs at temperatures of K and K. What is the coefficient of performance of the refrigerator?
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Ch 20: The Second Law of Thermodynamics
Young & Freedman Calc14th EditionUniversity PhysicsISBN: 9780321973610
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TOC.tableOfContents
- Ch 01: Units, Physical Quantities & Vectors41
- Ch 02: Motion Along a Straight Line67
- Ch 03: Motion in Two or Three Dimensions47
- Ch 04: Newton's Laws of Motion23
- Ch 05: Applying Newton's Laws59
- Ch 06: Work & Kinetic Energy14
- Ch 07: Potential Energy & Conservation8
- Ch 08: Momentum, Impulse, and Collisions18
- Ch 09: Rotation of Rigid Bodies42
- Ch 10: Dynamics of Rotational Motion48
- Ch 11: Equilibrium & Elasticity27
- Ch 12: Fluid Mechanics31
- Ch 13: Gravitation35
- Ch 14: Periodic Motion32
- Ch 15: Mechanical Waves25
- Ch 16: Sound & Hearing32
- Ch 17: Temperature and Heat36
- Ch 18: Thermal Properties of Matter38
- Ch 19: The First Law of Thermodynamics33
- Ch 20: The Second Law of Thermodynamics22
- Ch 21: Electric Charge and Electric Field36
- Ch 22: Gauss' Law24
- Ch 23: Electric Potential31
- Ch 24: Capacitance and Dielectrics18
- Ch 25: Current, Resistance, and EMF26
- Ch 26: Direct-Current Circuits30
- Ch 27: Magnetic Field and Magnetic Forces18
- Ch 28: Sources of Magnetic Field10
- Ch 29: Electromagnetic Induction28
- Ch 30: Inductance17
- Ch 31: Alternating Current21
- Ch 32: Electromagnetic Waves1
- Ch 33: The Nature and Propagation of Light20
- Ch 34: Geometric Optics34
- Ch 35: Interference19
- Ch 36: Diffraction25
- Ch 37: Special Relativity20
- Ch 38: Photons: Light Waves Behaving as Particles15
- Ch 39: Particles Behaving as Waves26
- Ch 40: Quantum Mechanics I: Wave Functions21
- Ch 41: Quantum Mechanics II: Atomic Structure25
- Ch 42: Molecules and Condensed Matter18
- Ch 43: Nuclear Physics16
- Ch 44: Particle Physics and Cosmology23
20장, 문제 21a
A sophomore with nothing better to do adds heat to kg of ice at °C until it is all melted. What is the change in entropy of the water?
검증된 단계별 안내1
Identify the process: The problem involves melting ice at 0°C, which is a phase change from solid to liquid. During this process, the temperature remains constant while the ice absorbs heat.
Calculate the heat absorbed (Q) during the melting process: Use the formula Q = m * L_f, where m is the mass of the ice (0.350 kg) and L_f is the latent heat of fusion for ice (approximately 334,000 J/kg).
Understand the concept of entropy change (ΔS): Entropy is a measure of disorder or randomness. For a reversible process at constant temperature, the change in entropy can be calculated using the formula ΔS = Q / T, where Q is the heat absorbed and T is the absolute temperature in Kelvin.
Convert the temperature from Celsius to Kelvin: Since the process occurs at 0.0°C, convert this to Kelvin by adding 273.15, resulting in T = 273.15 K.
Calculate the change in entropy (ΔS): Substitute the values of Q and T into the formula ΔS = Q / T to find the change in entropy of the water as the ice melts.
비슷한 문제에 대한 검증된 영상 답변:
이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.
영상 길이:
1m주요 개념
질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.
Entropy
Entropy is a measure of the disorder or randomness in a system. In thermodynamics, it quantifies the amount of energy in a physical system that is not available to do work. When heat is added to a system, such as melting ice, the entropy increases because the molecules become more disordered as they transition from a solid to a liquid state.
추천 영상:
가이드 코스
07:50
Intro to Entropy
Latent Heat of Fusion
The latent heat of fusion is the amount of heat required to change a unit mass of a solid into a liquid without a change in temperature. For ice, this is approximately 334,000 J/kg. This concept is crucial for calculating the heat added to melt the ice, which is necessary to determine the change in entropy.
추천 영상:
가이드 코스
10:40Latent Heat & Phase Changes
Thermodynamic Process
A thermodynamic process involves the transfer of heat and work into or out of a system, leading to changes in its state. In this scenario, the process is isothermal, meaning the temperature remains constant at 0°C while the ice melts. Understanding this helps in applying the formula for entropy change, ΔS = Q/T, where Q is the heat added and T is the absolute temperature.
추천 영상:
가이드 코스
08:45Properties of Cyclic Thermodynamic Processes
관련 실천
교과서 질문
You decide to take a nice hot bath but discover that your thoughtless roommate has used up most of the hot water. You fill the tub with kg of °C water and attempt to warm it further by pouring in kg of boiling water from the stove. Is this a reversible or an irreversible process? Use physical reasoning to explain.
1914
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교과서 질문
You make tea with kg of °C water and let it cool to room temperature (°C). Calculate the entropy change of the water while it cools.
1694
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교과서 질문
A -kg block of ice at °C melts to liquid water at °C inside a large room at °C. Treat the ice and the room as an isolated system, and assume that the room is large enough for its temperature change to be ignored. Is the melting of the ice reversible or irreversible? Explain, using simple physical reasoning without resorting to any equations.
2072
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교과서 질문
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 minutes of operation, the heat rejected by the engine melts kg of ice. During this time, how much work is performed by the engine?
2769
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교과서 질문
A -kg block of ice at °C falls into the ocean and melts. The average temperature of the ocean is °C, including all the deep water. By how much does the change of this ice to water at °C alter the entropy of the world? Does the entropy increase or decrease? (Hint: Do you think that the ocean temperature will change appreciably as the ice melts?)
411
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