Problem: A 6.4-cm-diameter, 10-cm-long cylinder contains 120mg of oxygen (O2) at a pressure less than 1 atm. The cap on one end of the cylinder is held in place only by the pressure of the air. One day when the atmospheric pressure is 100 kPa, it takes a 178N force to pull the cap off.
Part A: What is the temperature of the gas?
Please give me an explanation for this problem.