The viscosity of gas depends on the mass, the effective diameter and the mean speed of

The viscosity η of gas depends on the mass, the effective diameter and the mean speed of the molecules. Use dimensional analysis to find η as a function of these variables. Hence estimate the diameter of the methane (CH4) molecule given that η has values of 2.0 x 10-5 kgm-1s-1 for helium and 1.1 x 10-5kgm-1s-1 for methane at room temperature, and that the diameter of the helium atom 1.2.1 x l0-10 m. [Relative atomic manes for C and He are 12 and 4 respectively.]