The molecular mass of oxygen molecules is 32, and the molecular mass of nitrogen molecules is 28. If these two gases are at the same temperature, the ratio of nitrogen's rms speed to that of oxygen is ________.

The zeroth law of thermodynamics:  If two systems are in thermal equilibrium with a third system, then they are in thermal equilibrium with each other.

Boyle's law: The volume of a gas is inversely proportional to the absolute pressure applied to it when the temperature is kept constant.
Charles's law: The volume of a given amount of gas is directly proportional to the absolute temperature when the pressure is kept constant.
Gay-Lassac's law: At constant volume, the absolute pressure of a gas is directly proportional to the absolute temperature.