Physics · Heat, electricity and light. The idea in plain words, the rules to remember, the mistake to avoid and a worked example, written and checked by Mega Lecture.
The four laws set the rules for heat and work. The zeroth law defines temperature. The first law is conservation of energy for a system that exchanges heat and work. The second law gives the direction of natural processes: heat flows by itself only from hot to cold, and no engine can turn all the heat it takes in into work. The third law says absolute zero cannot be reached in a finite number of steps.
Entropy measures disorder, or the energy no longer available for work. In an isolated system it never decreases.
Kinetic theory explains gas pressure by molecules striking the walls. The absolute temperature measures the mean translational kinetic energy of the molecules.
Using temperatures in °C in the gas laws or the Carnot formula. Convert to kelvin first (add 273), or every ratio comes out wrong.
Answer: 40%; 400 J of work; 600 J rejected.
Type what you are stuck on. The helper finds the explanation, worked examples and the notes to read, free and instant.
← Oscillations and wavesElectrostatics and current electricity →Take a Physics test