A piston-cylinder device containing a fluid is fitted with a paddle wheel stirring device operated by the fall of an external weight of mass 50 kg. As the mass drops by a height of 5 m, the paddle wheel makes 10,000 revolutions. Meanwhile the free moving piston (frictionless and weightless) of 0.5 m diameter moves out by a distance of 0.7 m. Find the Wnet for the system if the pressure outside is 101 kPa.