Question 1,2 and 3

QUESTION 1 [10 Marks] A dead-weight gauge with a 1-cm-diameter piston is used to measure pressures very accurately. In a particular instance a mass of 6.14kg (including piston and pan) brings it into balance. If the local acceleration of gravity is 9.82m/s2, what is a) the gauge pressure being measured? (767.7kPa) b) the absolute pressure if the barometric pressure is 1atm ? (867.4kPa) (3) QUESTION 2 [10 Marks] A container holds 5kg of saturated water at 120C with quality of 0.6 , as sketched below: Determine, a) The volume of the liquid water; (0.00212m3) b) The volume of the vapour in the container; (2.676m3) (4) c) The pressure. ( 198.5kPa) (2) Question 3 [15 MARKS] 100kg of steam is enclosed in a piston-cylinder device, initial at 573.15K and 0.5 MPa. It expands and cools to 473.15K and 0.1MPa. a) What is the change in internal energy of this process? (-14 500kJ) (5) b) If the external pressure is constant at 0.1MPa, how much work was done by the steam on the surroundings? (-16 500kJ)