A wetting liquid rises through height h₀ in a capillary tube when the apparatus is stationary. The complete apparatus is then placed in an elevator accelerating vertically upward with acceleration a. Neglect changes in surface tension and density. What is the new capillary rise?
Options

Question

A wetting liquid rises through height h₀ in a capillary tube when the apparatus is stationary. The complete apparatus is then placed in an elevator accelerating vertically upward with acceleration a. Neglect changes in surface tension and density. What is the new capillary rise?

Options

G1 Physics · Accepted Answer

For a stationary capillary, h₀ = [2S cosθ] / [ρgr]. In an elevator accelerating upward, the effective gravity is g(eff) = g+a. Therefore, h = [2S cosθ] / [ρr(g+a)]. Divide this by the stationary expression: h/h₀ = g/(g+a). Hence, h = h₀g / (g+a). Correct option: B.