Rubber-block couplings: a) are also known as oldham couplings. b) dampen vibration. c) have two hubs with jaw-shaped flanges. d) have internal and external gear teeth.

For a process taking place in a closed system containing gas, the volume and pressure relationship is pvi-constant. -1.5 bar, the process starts with initial conditions, pi = =0.03 m3 and ends with final volume, v2-0.05 m3 determine the work done by the gas.