pls answer me asap. I really need help.

This is thermodynamic.

QUESTION 2 (25 MARKS] . a) A piston-cylinder device contains water at 400 C, 1-MPa and volume of 3 m.- The water is allowed to cool until the volume is reduce to half of the original volume at constant pressure. Calculate the amount of heat transfer (in KJ). (15 Marks) b) Refrigerant R-134a enters a diffuser steadily at 500 kPa as saturated vapor with a velocity of 140 m/s. It leaves the diffuser at 600 kPa and 50 C. Determine the heat transfer (in KJ/kg) during the process if the ratio of the inlet to exit area is 0.5. (10 Marks)