In an experiment similar to the Joule experiment (Fig. 1.1), an electric motor is used instead of a weight to stir the liquid. The thermal power PQ, assumed to result from the friction, is known. The coefficient c_M, which represents the heat per unit mass and temperature, is known and it is assumed to be independent of temperature.

a) Deduce the temperature rise ΔT after stirring for a time Δt.

b) Find an expression for the entropy variation ΔS during this process, which started at temperature T₀. 

Transcribed Image Text:

d I CX h V