AP Physics 2 Thermodynamics — practice questions
69 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice AP Physics 2 Thermodynamics in the app →In the first law of thermodynamics, ΔU = Q - W, the net heat transfer Q into a system is assigned a sign. WhatIn the same equation ΔU = Q - W, the net work W also carries a sign convention. According to the source, when How does the source define the internal energy U of a system, using the atomic and molecular point of view?A gas sample can reach the same pressure, volume and temperature by many different histories of heating, cooliHeat transfer and doing work are the two everyday ways of moving energy into or out of a system. How does the A system receives 40.00 J of heat transfer while it does 10.00 J of work. Afterward, 25.00 J of heat transfer In a second process on the same kind of system, heat transfer of 150.00 J leaves the system while 159.00 J of Nutritionists commonly use the dietary Calorie (capital C) to measure food energy. According to the source, hoBody fat can be converted into heat transfer and work done by the body. According to the source's discussion oA gas expands against a piston while a heater keeps the pressure constant throughout the process. What is thisOn a pressure versus volume diagram, certain paths are drawn as vertical lines, meaning the volume never changOn a pressure versus volume diagram for a gas, what quantity does the source say equals the work done on or byA gas undergoes a cyclical process, returning to its starting point on a pressure versus volume diagram and trIn a cyclical process on a pressure-volume diagram, a gas moves along segment AB at a constant pressure of 1.5Along segment CD of the same cyclical process, the gas is compressed at a constant pressure of 2.00 x 10^5 N/mThe full cyclical process ABCDA consists of isobaric segment AB doing 750 J of work, isochoric segment BC doinA gas is held at constant temperature while its pressure and volume are allowed to change together. If the gasAs an ideal gas expands isothermally, its volume increases while its temperature is kept fixed. What does the For a monatomic ideal gas undergoing an isothermal process, the total internal energy is U = (3/2)NkT, where NA gas expands adiabatically, meaning no heat transfer occurs during the process. According to the source, whatA process is described as one in which both the system and its surroundings can be brought back to exactly theThe source's usual convention treats the pressure inside a tank as the P used in W = PΔV, with work done by thA first statement of the second law of thermodynamics concerns the direction heat transfer takes between two bFriction can convert a moving object's kinetic energy entirely into thermal energy, warming its surroundings. A puff of gas is released into one corner of an otherwise empty vacuum chamber. According to the source, what None of the one-way processes described in the source, such as heat flowing only from hot to cold, actually viConsider an engine that undergoes a cyclical process, always returning to its initial state at the end of eachA heat engine completes a full cycle and returns exactly to its starting state, so its internal energy is unchThe source defines the efficiency Eff of a heat engine as a ratio of two quantities. Which ratio does it use?A coal-fired power station has 2.50 x 10^14 J of heat transfer from burning coal in one day, and 1.48 x 10^14 Using the work output of 1.02 x 10^14 J found for that same coal-fired power station, and the 2.50 x 10^14 J oThe Otto cycle used to model the four-stroke gasoline engine is drawn as a closed loop on a pressure-volume diWho first worked out, at a theoretical level, the maximum possible efficiency of a heat engine, and in what yeWhat is described as the single feature that defines the Carnot cycle and sets it apart from other cyclical prAccording to Carnot's theorem as restated in the source, how does the efficiency of a Carnot engine compare wiWhat formula does the source give for the Carnot efficiency, EffC, in terms of the cold and hot reservoir tempA nuclear reactor has pressurized water at 300°C acting as the hot reservoir, and steam is eventually condenseNo real heat engine ever reaches its theoretical Carnot efficiency. According to the source, roughly what fracCarnot's result implies that a heat engine could reach 100% efficiency only under one specific condition on thDespite having the greatest possible theoretical efficiency, why does the source say the ideal Carnot engine iHeat pumps, air conditioners and refrigerators all move heat transfer from a cold reservoir to a hot one, whicFor a heat pump, work input W drives heat transfer Qc out of a cold reservoir into a hot reservoir. How does tA simple heat pump used for home heating contains four basic components arranged in a loop. According to the sThe source defines a heat pump's coefficient of performance, COPhp, as a ratio of two quantities. Which ratio Since a heat engine's efficiency is Eff = W/Qh, and a heat pump's coefficient of performance is COPhp = Qh/W, Since COPhp = 1/Eff and the Carnot efficiency EffC = 1 - Tc/Th shrinks as Tc and Th get closer together, what A heat pump for a home has a hot reservoir temperature of 45.0°C and a cold reservoir temperature of -15.0°C. Real heat pumps never reach the ideal coefficient of performance found for a Carnot cycle between the same twoFor an air conditioner or refrigerator, the source defines a separate coefficient of performance, COPref. WhicRoom air conditioners are often rated with a non-SI quality measure called the energy efficiency rating, EER, The source introduces entropy as a way of restating the second law of thermodynamics in yet another form. WhatFor a reversible process, the source defines the change in entropy ΔS using heat transfer Q and absolute tempeJust as internal energy U depends only on a system's current state, what does the source say about entropy S iConsider a full cycle of a Carnot engine, in which the hot reservoir loses entropy -Qh/Th and the cold reservoIn an irreversible process, 4000 J of heat transfer occurs from a hot reservoir at 600 K to a cold reservoir aThe source restates the second law of thermodynamics one more time, this time in terms of the total entropy ofA Carnot engine operating directly between 600 K and 100 K produces 3333 J of work from 4000 J of heat transfeOne kilogram of ice at 0°C melts into water at 0°C. The latent heat of fusion for water is 334 kJ/kg. What is Equal masses of water at 20.0°C and 40.0°C are mixed together, settling to a single intermediate temperature oLiving organisms evolve into highly structured forms, meaning their entropy is much lower than that of the simWhen describing the possible outcomes of tossing several coins, the source distinguishes between an overall prFor the same set of coin tosses, the source also names the fully detailed description that specifies exactly wFor a toss of 5 coins, how many total macrostates are possible when counting only by total heads and tails, anTable 15.3 shows that the macrostate of 3 heads and 2 tails corresponds to 10 different microstates, while theFor a toss of 100 coins, Table 15.4 gives the number of microstates for each macrostate, with a grand total ofIf someone tossed 100 coins once every second, according to the source, about how often would they expect to lThe source applies the idea of macrostates and microstates to a real gas sample. How many atoms does it say arLudwig Boltzmann connected entropy to the probability of a macrostate occurring, using the number of microstatTossing 100 coins starting from 60 heads and 40 tails (with Wi = 1.4 x 10^28 microstates) eventually lands on