A person pushing a uniformly$-$loaded $35\mathrm{.}7$kg wheelbarrow of length L with pushing force P is attempting to get it over a step. The maximum horizontal force that the person can apply is Px$=457$N$.$ What is the maximum height h of the step, expressed as a fraction n of the wheel's radius R$,$ that the person can get the wheelbarrow over? The gravitational acceleration is g$=9\mathrm{.}81$m$/$s$2.$