2013-3-1 Change in Internal Energy The change in intemal energy is associated with the makeup of the system,including its chemical composition. There is no simple expression for evaluating internal energy change for a wide range of applications.In most cases we will evaluate internal energy change using data from tables in appendices of the textbook Like kinetic and gravitational potential energy, internal energy is an extensive property. Internal energy is represented by U. The specific internal energy on a mass basis is u The specific internal energy on a molar basis is a 2-11 Change in Energy of a System In engineering thermodynamics the change in energy of a system is composed of three macroscopic contributions: Kinetic energy Gravitational potential energy Internal energy(all other energy changes are lumped together) Total energy and internal energy are also extensive properties. 2-12 6 2013-3-1 6 Change in Internal Energy u. 2-11 ►The change in internal energy is associated with the makeup of the system, including its chemical composition. ►There is no simple expression for evaluating internal energy change for a wide range of applications. In most cases we will evaluate internal energy change using data from tables in appendices of the textbook. ►Like kinetic and gravitational potential energy, internal energy is an extensive property. ►Internal energy is represented by U. ►The specific internal energy on a mass basis is u ►The specific internal energy on a molar basis is ū Change in Energy of a System 2-12 In engineering thermodynamics the change in energy of a system is composed of three macroscopic contributions: ►Kinetic energy ►Gravitational potential energy ►Internal energy (all other energy changes are lumped together) Total energy and internal energy are also extensive properties