17.1 Example 1

700 cal are given to a thermodynamic process, while the system made a work of 200 J. How many change the internal energy?

Solution with FisicaLab

The problem statement don’t specify the type of thermodynamics process, so we can assume it is an isobaric process witn an arbitrary mass, pressure and initial temperature. Then select the Thermodynamics group and, inside this, the Thermodynamics module. Erase the content of the chalkboard. And add one element Isobaric process, one element Applied heat and one element Work. As show the image below:

To the isobaric process, we set 1 kg to mass, 1 pascal to pressure and 1 m^3 to initial volumen. Then:

Name

0

m

1

dU

U

P

1

Vi

1

Vf

Vf

To the element Applied heat:

Q

700 @ cal

And to the element Work:

W

200

Now click in the icon Solve to get the answer:

U = 2312.080  J ;
Vf  =  201.000  m3;
Status = success.