physics 3B workbook: thermodynamics© 2009 Pearson Education, Inc.This work is protected by United States copyright laws and is provided solely for the use of instructors in teaching their courses and assessing student learning. Dissemination or sale of any part of this work (including on the World Wide Web) will destroy the integrity of the work and is not permitted. The work and materials from it should never be made available to students except by instructors using the accompanying text in their classes. All recipients of this work are expected to abide by these restrictions and to honor the intended pedagogical purposes and the needs of other instructors who rely on these materials.Additional © 2016 Laura Tucker2Thermodynamics overviewThe previous physics class discussed mechanical energy: kinetic and potential energy of the center of mass. We now learn about non-mechanical (internal) energy. Kinds of non-mechanical energy include thermal energy, chemical energy, nuclear energy.Thermal energy is energy due to the motion and potential energies of particles that compose a material. Thermal energy depends on the temperature and phase of a material.3(c) Which of the following best describes mechanical energy? A. It is the kinetic and potential energy of the center of massB. It is the kinetic and potential energy of the individual particles comprising an object4Mechanical energy is calculated using the motion and position of A. the center of massB. the individual particles comprising an object6On which quantities does thermal energy depend?i. the velocity of the center of massii. the temperature of the objectiii. the phase of the objectiv. the height of the objectA. i and ii onlyB. i, ii, iii, and ivC. i and iii onlyD. ii and iii onlyE. i, ii, and iii only8What is the difference between the speed that particles have due to thermal energy and the speed that is used to calculate the kinetic energy of an object?A. the thermal energy speed describes the speed of particles between collisions with other particles, while the kinetic energy speed describes the overall speed of the objectB. the kinetic energy speed describes the speed of particles between collisions with other particles, while the thermal energy speed describes the overall speed of the object10Solids, liquids and gases are collections of particles, which can be moving even when they appear still. The extent that they move is based on their state (e.g. solid, liquid, or gas) and temperature.17-1 Atomic Theory of MatterOn a microscopic scale, the arrangements of molecules in solids (a), liquids (b), and gases (c) are quite different.Gas particles move to the largest extent and with the highest speeds compared to the other phases.17-1 Atomic Theory of Matter14(c) In which state do the particles of a material generally have the highest speeds?A. solidB. liquidC. gasD. speeds are equal at a given temperature, regardless of phaseBrownian motion is the jittery motion of tiny flecks in water; these are the result of collisions with individual water molecules.Brownian motion shows that even when water appears still, the water molecules are moving due to their thermal energy.17-1 Atomic Theory of MatterIn kinetic theory, we look at particles in an ideal gas. We assume these particles collide with one another and walls of their container in perfectly elastic collisions (no energy lost). 18-1 The Ideal Gas Law and the Molecular Interpretation of TemperatureWe can analyze the force due to a change in momentum to calculate the pressure and then the kinetic energy in the gas. You are not responsible for the derivation steps, but you should know the result.The average translational kinetic energy of the molecules in an ideal gas is directly proportional to the temperature (in Kelvin) of the gas.18-1 The Ideal Gas Law and the Molecular Interpretation of Temperature(c) In kinetic theory, we look at an ________ and find that its internal energy depends on _____________.A. ideal gas, the temperature of the gasB. any solid, the temperature of the solidC. any material, the temperature of the materialD. any liquid or gas, the mass of the particles in the material 2018-1 The Ideal Gas Law and the Molecular Interpretation of TemperatureExample 18-1: Molecular kinetic energy.What is the average translational kinetic energy of molecules in an ideal gas at 37°C?Thermodynamics overviewFrom the law of conservation of energy, we know that work done on a system by external forces can add to or take away energy from a system.23Thermodynamics overviewHeat is energy transferred from one object to another due to a difference in temperature.24Heat is A. energy transferred between objectsB. internal energy that is related to the temperature of the objectC. both (a) and (b) are true25We often speak of heat as though it were a material that flows from one object to another; it is not. Rather, it is a form of energy.Unit of heat: calorie (cal)1 cal is the amount of heat necessary to raise the temperature of 1 g of water by 1 Celsius degree.Don’t be fooled—the calories on our food labels are really kilocalories (kcal or Calories), the heat necessary to raise 1 kg of water by 1 Celsius degree.19-1 Heat as Energy Transfer4.186 J = 1 cal4.186 kJ = 1 kcal19-1 Heat as Energy TransferExample 19-1: Working off the extra calories.Suppose you throw caution to the wind and eat too much ice cream and cake on the order of 500 Calories. To compensate, you want to do an equivalent amount of work climbing stairs or a mountain. How much total height must you climb?The sum total of all the energy of all the molecules in a substance is its internal (or thermal) energy.Temperature: measures molecules’ average kinetic energyInternal energy: total energy of all moleculesHeat: transfer of energy due to difference in temperature19-2 Internal EnergyThermodynamics overviewHeat is energy generally used by a material to raise the temperature of the material or change the phase of the material.30The amount of heat required to change the temperature of a material is proportional to the mass and to the temperature change:The specific heat, c, is characteristic of the material. Some values are listed at left.19-3 Specific Heat19-4 Latent HeatEnergy is required for a material to change phase, even though its temperature is not changing.You have a block of ice to which you add 13 kcal of heat. The temperature does not change. What likely happened to that energy?A. It was transferred