Physics 3.3 First Law of Thermodynamics Exam Questions with Complete Solutions

First Law of Thermodynamics - ANSWER-energy can be transferred and transformed, but it cannot be created or destroyed the total internal energy of a system is equal to the amount of heat added minus the work done on the system First Law of Thermodynamics Equation - ANSWER-delta U=Q-W Q= heat energy W=work done on the system delta U= change in the system's internal energy Change in internal energy (equation) - ANSWER-ΔU decreasing temp= negative increasing temp = positive Heat (equation) - ANSWER-heat flows into the system (positive) heat is lost from the system (negative) Work (equation) - ANSWER-work is done by the system (expansion) positive work is done on the system (compression) negative Heat can be measured by - ANSWER-calorie (cal), nutritional calorie (Cal), British thermal unit (BTU), joule (J) 1 Cal= 10^3cal =4184 J = 3.97 BTU Heat - ANSWER-process of energy transfer between two objects at different temperatures that occurs until two objects come into thermal equilibrium Specific Heat - ANSWER-the amount of energy required to raise the temperature of 1 gram of a substance by 1 degree Celsius or 1 Kelvin Specific Heat of Water - ANSWER-1 cal/g*K 4.184 J/gC