An open-end manometer containing mercury is connected to a container of gas, as depicted in Sample Exercise 10.2 in the textbook. What is the pressure of the enclosed gas in torr in each of the following situations? Part A: The mercury in the arm attached to the gas is 15.0 cm higher than in the one open to the atmosphere; atmospheric pressure is 0.975 atm . Part B: The mercury in the arm attached to the gas is 12 mm lower than in the one open to the atmosphere; atmospheric pressure is 0.97 atm.