Water strider surface tension model · IZhO 2021 #1.2
Physics · fluid-mechanics
Problem
Some insects, such as water striders, are capable of moving freely on the water surface, because their legs are densely covered with non-wetting hairs. To understand why this turns possible, consider the following model problem. A square plate with the side a=10.0 cm and thickness h=2.00 mm is carefully laid on the water surface. The density of the plate material is equal to ρ=1.10 g/cm³, the density of water is ρ0=1.00 g/cm³, and its surface tension constitutes σ=7.30⋅10−2 N/m. Find the maximum mass m of a weight that can be put on the plate so that it still does not sink. Assume that the weight does not deform the plate, the acceleration of free fall is g=9.80 m/s².