Question

We consider tobacco virus diffusing along a 0.47 m long tube filled with water. The cross-sectional area of the tube is unknown. The diffusion coefficient is found in Table 10.5, p. 319 in the textbook. A total amount of virus of 2.6 x 10-16 kg is transported in a steady state along the tube in 0.20 minutes. If the difference in the density levels of virus at the two ends of the tube is 0.07 g/cm3, what is the cross-sectional area of the tube?

Answer 1

I don't have your textbook. You should look for the diffusion coefficient yourself, since your problem is URGENT. Call it D. It should have dimensions of something like cm^2/s.

The transport rate of the virus will be
D*(density2 - density1)*Area/L = 2.17*10^-13 g/sec

Solve for the area A.