Physics is explicitly involved in studying which of these activities?
a. the mixing of metals to form an alloy
b. the metabolic functions of a living organism
c. the motion of a spacecraft under gravitational influence
d. the depletion of the atmospheric ozone layer due to pollutants
e. the killing of cancerous cells by radiation therapy

Arigid tank is divided into two equal parts by a partition. one part of the tank contains 3 kg of compressed liquid water at 400 kpa and 60°c while the other part is evacuated. the partition is now removed, and the water expands to fill the entire tank. determine the entropy change of water during this process, if the final pressure in the tank is 40 kpa. use steam tables.