2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/108165Modified Newtonian dynamics can be considered as an effect derived from a squeezable extra dimension space. The third law of Newtonian dynamics can be managed to remain valid in the 5-space. The critical acceleration parameter $a_0$ appears naturally as the bulk acceleration that has to do with the expanding universe in this setup. A simple toy model is presented in this Letter to show that consistent theory can be built with the help of the extra dimensional space.4 pages, 1 figureAstrophysicstext