A cubical block of side a and density ρ slides down a fixed plane inclined at 37° with constant speed v. A viscous liquid film of thickness t lies between block and plane. Find the coefficient of viscosity. Image
Options

Question

A cubical block of side a and density ρ slides down a fixed plane inclined at 37° with constant speed v. A viscous liquid film of thickness t lies between block and plane. Find the coefficient of viscosity. Image

Options

G1 Physics · Accepted Answer

Step 1: Use surface-energy/pressure relations: ΔP = 2T/R for a liquid drop or 4T/R for a soap bubble, capillary rise h = 2T cosθ/(ρgr), and surface energy = TΔA. Step 2: Apply force or energy balance to the stated radii and surface areas. Applying these relations to the given data gives A: 3ρagt/(5v). Final answer: A.