21.1 Instead of the arrangement in Fig. 21.8, the speed of molecules can also be measured with a rotating slotted-disc apparatus, which consists of five coaxial 5.0cm diameter discs separated by 1.0cm, the slots in their rims being displaced by 2.0 between neighbours. The relative intensities, I, of the detected beam of Kr atoms for two different temperatures and at a series of rotation rates were as follows: Find the distributions of molecular velocities, f(vx), at these temperatures, and check that they conform to the theoretical prediction for a one-dimensional system