PHYSICS · Single correct · AP · Physics 1: Algebra-based · Fluids · Fluids
Problem
During an experiment, a single gas molecule strikes a flat wall, exerting a force of magnitude F at an angle of 30∘ to the normal of the wall. Which statement best describes how this interaction contributes to the macroscopic pressure on the wall?
(a) Both components contribute, so the wall experiences Fcos30∘+Fsin30∘ when computing pressure.
(b) Only the component Fcos30∘ contributes because pressure depends on the force perpendicular to the surface.
(c) Because the molecule rebounds, the effective force normal to the wall is 2Fcos30∘ when determining pressure.
(d) The entire magnitude F contributes because pressure is force per unit area independent of direction.