In the figure below, the change in internal energy of a gas that is taken from A
ID: 1495028 • Letter: I
Question
In the figure below, the change in internal energy of a gas that is taken from A to C along the blue path is +790 J. The work done on the gas along the red path ABC is -505 J. (a) How much energy must be added to the system by heat as it goes from A through B to C? J (b) If the pressure at point A is five times that of point C, what is the work done on the system in going from C to D? J (c) What is the energy exchanged with the surroundings by heat as the gas goes from C to A along the green path? J (d) If the change in internal energy in going from point D to point A is +480 J, how much energy must be added to the system by heat as it goes from point C to point D? J
Explanation / Answer
A) energy to be added = chage in internal energy - work done on the gas
= 790 + 505 = 1295 J
b) Work done in process C to D = - (1/5)*Work done on system in Ato B
= - 505/5 = -101 J
C) Energy exchanged =790 +101 = 891 J
d) Energy to be added = 790-480 = 310 J