Below a certain threshold pressure, the air molecules (0.3 nm diameter) within a research vacuum chamber are in the "collision-free regime", meaning that a particular air molecule is as likely to cross the container and collide first with the opposite wall, as it is to collide with another air molecule. Estimate the threshold pressure for a vacuum chamber of side 1,0 m at 20 °C.

Large helium-filled balloons are used to lift scientific equipment to high altitudes. a) What is the pressure, in atmospheres, inside such a balloon if it starts out at sea level with a pressure of one atmosphere and a temperature of 10.0°C and rises to an altitude where its volume is twenty times the original volume and its temperature is -49.5°C ?  b) What is the gauge pressure, in atmospheres, in the balloon then? (Assume the atmospheric pressure is constant.)

What is the RMS speed of Helium atoms when the temperature of the Helium gas is 312.0 K? (Possibly useful 1.66x10-27 kg, Boltzmann's constants: the atomic mass of Helium is 4.00 AMU, the Atomic Mass Unit is: 1 AMU constant is: kg = 1.38×10-23 J/K.) kB Submit Answer Tries 0/12 What would be the RMS speed, if the temperature of the Helium gas was doubled? Submit Answer Tries 0/12 =

A balloon is filled with helium gas at atmospheric pressure (1 atm) until its volume is 800 m³. The helium gas is then transferred to cylinders that have a volume of 2.3 m³ at a pres- sure of 13.3 atm. Calculate the number of cylinders used. Assume that the temperature of the helium gas remains constant. (1 atm = 1.013 × 105 Pa).