**P. 3840.** A sample of gas was compressed to a volume of 20 l adiabatically so the gas did not release or absorbe heat. The initial pressure was 101.3 kPa and was increased by 76.4% during the process. *a*) Calculate the change in the energy of the gas. *b*) Find the change of the entropy of the gas. *c*) By what factor did the absolute temperature of the gas increased?

(4 points)

**Deadline expired on 12 December 2005.**