Griffith's saying that in a resistor, P = RI² is the rate at which heat is disipated. Is that suposed to be intelligible to someone who has no knowledge in thermodynamics? Can someone explain this process to me. What is HEAT? And how does the rate at which work is being done by the electrostatic force on the electrons in the resistor a measure in all point equal to that of the rate at which heat is dissipated?