The mine is 100 m deep. On the surface, the pressure is 752 mm Hg. What is the pressure at the bottom of the mine.

Near the surface of the Earth, for changes in altitude of several hundred meters, it can be roughly assumed that when rising by 10 m, atmospheric pressure decreases by 1 mm Hg. Art., and when descending by 10 m – decreases by 1 mm Hg. Art.

Descent into the mine by 100 m corresponds to ten descents of 10 m, which means the atmospheric pressure will increase by 10 mm Hg. Art. and will be 752 + 10 = 762 mm Hg. Art.