Energy, Heat, & Thermodynamics and Heat Transfer Vocabulary Exam Questions with Latest Update

conservation of energy - ANSWER-Conservation of Energy Formula. An object, or a closed system of objects, can have both kinetic and potential energy. ... If no outside forces act on the system, then the total mechanical energy is conserved. Energy can change from kinetic to potential energy, and back, without reducing the total energy. potential energy - ANSWER-For the gravitational force the formula is P.E. = mgh, where m is the mass in kilograms, g is the acceleration due to gravity (9.8 m / s2 at the surface of the earth) and h is the height in meters. Notice that gravitational potential energy has the same units as kinetic energy, kg m2 / s2. kinetic energy - ANSWER-Kinetic and Potential Energy. ... Kinetic energy is directly proportional to the mass of the object and to the square of its velocity: K.E. = 1/2 m v2. If the mass has units of kilograms and the velocity of meters per second, the kinetic energy has units of kilograms-meters squared per second squared. chemical energy - ANSWER-Define enthalpy of reaction as the energy release in a reaction and the work done by the system. The enthalpy of formation is as indicated: H2(g) + 0.5 O2 -> H2O(l), dHf = -285.8 kJ/mol Calculate the enthalpy of reaction when 1 mole of O2 reacts with 4 moles of H2 at the standard conditions. thermal energy - ANSWER-SI unit of thermal energy is Joules(J). The formula for finding thermal energy is given as, Where Q is the thermal energy, m is the mass of the given substance, c is the specific heat and ΔT is the temperature difference. mechanical energy (total mechanical energy) - ANSWER-As already mentioned, the mechanical energy of an object can be the result of its motion (i.e., kinetic energy) and/or the result of its stored energy of position (i.e., potential energy). The total amount of mechanical energy is merely the sum of the potential energy and the kinetic energy. Work - ANSWER-Work, in physics, measure of energy transfer that occurs when an object is moved over a distance by an external force at least part of which is applied in the direction of the displacement. Joules - ANSWER-Kinetic energy is a scalar quantity; it does not have a direction. ... Like work and potential energy, the standard metric unit of measurement for kinetic energy is the Joule. As might be implied by the above equation, 1 Joule is equivalent to 1 kg*(m/s)^2.