A possible ideal-gas cycle operates as follows:

i. from an initial state (p1,V1) the gas is cooled at constant pressure to (p1,V2);
ii. the gas is heated at constant volume to (p2,V2);
iii. the gas expands adiabatically back to (p1 , V1 ).

Assuming constant heat capacities, show that the thermal efficiency is

Asolid cylinder is concentric with a straight pipe. the cylinder is 0.5 m long and has an outside diameter of 8 cm. the pipe has an inside diameter of 8.5 cm. the annulus between the cylinder ad the pipe contains stationary oil. the oil has a specific gravity of 0.92 and a kinematic viscosity of 5.57 x 10-4 m2/s. most nearly, what is the force needed to move the cylinder along the pipe at a constant velocity of 1 m/s?