Flashcards on Work, Energy, and Power

Work, Energy, and Power: A Comprehensive Student Guide

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Why can't all thermal energy be converted into useful work in a heat engine?

Because thermal energy is the energy of random particle motion and tends to spread out; as it disperses, it becomes less concentrated and less useful

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Energy: Heat Engines

16 cards

Card 1

Question: Why can't all thermal energy be converted into useful work in a heat engine?

Answer: Because thermal energy is the energy of random particle motion and tends to spread out; as it disperses, it becomes less concentrated and less useful

Card 2

Question: What does it mean for thermal energy to 'spread out,' and why does this reduce its usefulness?

Answer: It means the energy is distributed among more particles and over a larger volume; as it disperses, the same amount of energy creates a smaller tempera

Card 3

Question: Give an example that illustrates how the dispersion of thermal energy makes it less useful.

Answer: Energy concentrated in a hot flame can generate steam for a turbine, but if that same energy is distributed throughout a large body of water, it will

Card 4

Question: What are 'district heating' systems in relation to a thermal power plant?

Answer: These are systems that collect unused heat from a power plant using hot water pipes to warm nearby homes, offices, and factories, utilizing energy tha

Card 5

Question: Why might a power plant operate with lower efficiency to facilitate district heating?

Answer: Because by slightly lowering efficiency, hotter water can be produced, which is more useful for supplying heat to the urban network.

Card 6

Question: In a combined cycle gas turbine power plant, how are the two sources of electricity generation obtained?

Answer: First, gas combustion drives a jet-engine-type turbine that spins a generator; then, the hot exhaust gases are used to produce steam, which powers a s

Card 7

Question: List four different types of fuel used in thermal power plants (according to the provided content).

Answer: The content asks to list fuels; examples mentioned in the material include: natural gas (in combined cycle), coal (plant X is coal-fired), nuclear fue

Card 8

Question: In a thermal power plant, what is the produced steam used for?

Answer: The steam is used to drive the turbines, which spin the generators to produce electricity.

Card 9

Question: What is the function of cooling towers in a thermal power plant?

Answer: To remove excess heat (disperse thermal energy not converted into work) by cooling and condensing the steam to recycle it through the cycle.

Card 10

Question: According to the given table, where is most of the energy wasted in power plants X and Y?

Answer: The greatest loss occurs in the turbines: 2900 MW in plant X and 3800 MW in plant Y.