Choose the BEST answer to the following: Heat engines, such as a jet engine, are more efficient when run at (a) high temperatures. (b) constant temperatures. (c) low temperatures. (d) a constant rate.

Q: A heat engine with a thermal efficiency of 45 percent rejects 500 kJ/kg of heat. How much heat does…

A: Given:  Efficiency = 45 %  heat rejected, QC = 500 kJ/kg

Q: How do meteorologist express the first law of thermodynamics?

A: Meteorologists express the first law of thermodynamics as follows:  Air temperature increases as the…

Q: How an ice box or refrigerator keep things cold for a long time?

A: Refrigerator works based on the principle heat is taken from the source at a higher temperature and…

Q: Which contains more heat, a coffee cup of boiling water or a bathtub with water at room temperature?

A: An average size bathtub contains 250 kg of water and an average size cup contains 0.25 kg of water.…

Q: Which law of thermodynamics allow us to use a thermometer that only tells you its own temperature?

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Q: In what direction does internal energy flow between hot and cold objects?

A: When two bodies, one hot and the other one cold comes in contact, the hotter body cools down and the…

Q: Heat and temperature have the same meaning. O True O False

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Q: How does specific heat relate to how fast a substance changes temperature?

A: The heat loss, ∆H, from a substance of mass m and specific heat s, is related to the change in…

Q: The human body loses heat at a rate of 120 W when sitting quietly at rest. If a 65-kg student takes…

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Q: What happens if the calorimeter is not covered properly?

A: Calorimeter or bomb calorimeter is defined as a apparatus used for measuring the amount of heat…

Q: Defend the statement that 100% of the electrical energy that goes into lighting a lamp is converted…

A: The statement that 100% of the electrical energy that goes into lighting a lamp is converted to…

Q: How does the law of the conservation of energy relate to the first law of thermodynamics?

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Q: Which will normally warm faster - a black pot of cold water or a silvered pot of cold water?…

A: The black pot of cold water will normally warm faster than the silvered pot of cold water.

Q: Is it the boiling of water or the higher temperature of water that cooks food faster in a pressure…

A: Food can be cooked more quickly in a pressure cooker.

Q: How does the second law of thermodynamics relate to the direction of heat flow?

A: Let us understand this with an example. A hot cup of coffee is kept in open atmosphere.

Q: What is a heat pump?

A: Heat pump is a device that is used for transfer of heat in and out of the system. When it's cold…

Q: What does it mean to say that two systems are in thermal equilibrium?

A: What does it mean to say that two systems are in thermal equilibrium?

Q: why a metal spoon left in a pot of boiling water gets hot so fast ?

A: In metals heat transfer takes place by conduction . In conduction heat transfer takes place by…

Q: What is third law of thermodynamics? How does it lead us to the concept of absolute zero?

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Q: What are the application of heat and work in thermodymics in daily life?

A: We have to mention the application of heat and work in thermodynamics in daily life.

Q: The same amount of heat flows into two non-identical bowls of soup, which are initially at the same…

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Q: Why is thermal equilibrium always established when two objects transfer heat?

A: Heat is a form of energy that transfers from higher temperature to the lower temperature. At higher…

Q: A power station with an efficiency of 0.4 generates 108 W of electric power and dissipates 1.5 × 108…

A: The heat energy required to raise the temperature of a substance is given by,

Q: How does the second law relate to heat engines?

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Q: You are cold, so you cover yourself in a blanket. A half hour later, you feel much warmer. Explain…

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Q: What is thermodynamic identity ?

A: To determine: What is meant by thermodynamic identity?

Q: Does human body follow laws of thermodynamics?

A: Yes, it completely does. An example of the same is when you are sitting in a crowded room, you tend…

Q: What is meant by thermodynamics?

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Q: Compared to a giant iceberg, a hot cup of coffee has more what? (A) Thermal energy and higher…

A: Compared to a giant iceberg, a hot cup of coffee has more  a higher temperature, but less thermal…

Q: The heat never flows spontaneously from a colder object to a hotter object. why?

A: Heat flows

Q: MAKING CONNEC TIONS 13. When you apply heat energy to a substance, where does the energy go? Think…

A: Conservation of energy says energy is neither be created nor can be destroyed, it just changes it’s…

Q: In buildings that are being electrically heated, is it at all wasteful to turn all the lights on? Is…

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Q: Rank the magnitudes of these units of thermal energy from greatest to least: a. 1 calorie b. 1…

A: Calorie is the amount of heat required to raise temperature from 14.5 0 C to 15.50 C of 1 gram…

Q: How does the concept of thermodynamics help you and the world in the future?

A: Thermodynamics explains the working of refrigerators and heat engines. They help in designing these…

Q: What are the three systems in Thermodynamics?

A: There are a total of three systems in thermodynamics, which are : Isolated System - An isolated…

Q: Which law of thermodynamics tackles the role of insulators and conductors in heat flow: zeroth,…

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Q: What does it mean to say that human body is an engine with an efficiency of 20 percent?

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Q: Distinguish between a calorie and a joule?

A: Both calorie and joule are the units of energy. The main difference in both the units is that a…