Ncert Exercises & Solutions

Consider a rectangular block of wood moving with a velocity $v_{0}$ in gas at temperature T and mass density $ρ$ . Assume the velocity is along the x-axis and the area of cross-section of the block perpendicular to $v_{0}$ is A. Show that the drag force on the block is $4 ρ A_{V_{0}} \sqrt{\frac{k T}{m}}$ , where m is the mass of the gas molecule.