Question

Question 1: A cylindrical mine shaft has a large 10 tonne plug inserted over the opening. The plug seals the shaft completely. A schematic of the shaft is shown in Figure 1. You can assume that the plug is infinitesimally thin (i.e. don't consider the thickness of the plug in the analysis) and that there is no friction at the walls. a) Assuming isothermal compression, at which depth will the mass come to a rest? (4pts) b) i) Assuming constant pressure, how much work into the gas is required to lift the mass back to ground level? (4pts) ii) What is another way of calculating the energy required to move the plug back to ground level, and, how do the results compare? (2pt) Om 10t latm 25°C -15m Figure 1: Mine shaft schematic

Answer 1