In which case does the metal have the largest work function?

I am doing some practice problems to prepare for an exam and i cannot solve this problem, specifically part a but I would like to check this problem A piston cylinder device contains 0.8 kg of air initially at 100 kPa, 27 °C. The air is now compressed slowly in a polytropic process during which PV^1.3 =constant, until the volume reaches 1/2 its original volume. The system is then heated at constant pressure until the volume gets back to its original value. NOTE: THIS IS NOT A CYCLE. Data: Rair = 0.287 kJ/kg K; Cv=0.731 kJ/kg K; Cp=1.018 kJ/kgK. a)  Determine the amounts AND directions of the Work and Heat(each in kJ) for each of the two processes. show all work used to get your values. b)   Sketch the two processes on a P-v diagram, clearly showing all three state points and the two processes with their directions.

Problem 3 A power plant produces 1500 MWe with an efficiency of 35 %. Assuming this is a coal-fired plant, (a) calculate how much bituminous coal does it burn in an hour? (b) Estimate how much heat in Joules is released to the environment per second? Assume that the energy content of bituminous coal is 31 MJ/kg. Problem 4 **

A 12 g bullet is fired from a gun and moves vertically upwards at a velocity of 950m/s and strikes a 2kg brick which is originally at rest, as shown in the picture below. If the bullet emerges from the brick at a speed of 290m/s, determine 1. What is the The maximum height to which the brick rises? 2. What is The increase in the internal energy of the whole bullet-brick system? 290 m/s 950 m/s

Determine which of the following are true or false and explain your answer: a) During an isothermal process, the entropy of an ideal gas stays constant if there is a net change in either pressure or volume b) Entropy generation takes place when there are irreversibilities in a cycle. c) The lower the isentropic efficiency of a turbine, the more power it will generate with the same input stream and same output pressure.

A gas at a fixed volume had a temperature change from 187.00 K to 65.25 K. At 65.25 K, the pressure was recorded as 188 Pa. What was the initial pressure? *USE THE EQUATION FOR GAY-LUSAAC’S LAW