A Swiss watchmaker states in a flyer the mechanical power PW dissipated by a  specific clock (Fig. 2.10). The work provided to the clock is due to the temperature

Figure 2.10

A clock receives its energy from the gas capsule (shaded area). The gas expands and contracts under the effects of  the temperature fluctuations in the room. fluctuations ΔT around room temperature T that let the clock run during a time t.  We consider that the atmospheric pressure p_ext is equal to the pressure of the gas p,  i.e. p_ext = p. The pressure p and the volume V of the gas are related by the ideal gas  law pV = NR T where R is the ideal gas constant. Consider that the gas in the capsule  is always at equilibrium with the air outside of the capsule (pressure and temperature  are the same inside and outside). From the watchmaker’s information, estimate the  volume V of the gas capsule used to run this clock.

Numerical Application:

Transcribed Image Text:

Pw = 0.25. 10-6 W, T = 25°C, AT = 1°C, p ext = 105 Pa and t = 1 day.