In An Ultra High Vacuum System The Pressure Is Measured To Be 1 00 X 10 10 Torr

In an ultra-high-vacuum system, the pressure is measured to be 1.00 X 10-10 torr (where 1 torr = 133 Pa). Assuming the molecular diameter is 3.00 % 10-10 m, the average molecular speed is 500 m/s, and the temperature is 300 K, find(a) The number of molecules in a volume of 1.00 m3,(b) The mean free path of the molecules, and(c) The collision frequency.