Gaseous methane is compressed polytropically by a piston from 250C and 0.80 bar to a pressure of 5.0 bar. Assuming an index of compression of 1.2, calculate the change of entropy and work done, per unit mass of the gas. The relative molecular mass of methane is 16 and = 1.30.

What is the chief metrological difference between measuring with a microscope and with an electronic comparator? a. the microscope is limited to small workpieces.a. the microscope is limited to small workpieces. c. the comparator can only examine one point on the workpiece. d. the microscope carries its own standard.