I am looking for a solution to the arrowheads have different sizes for each arrow, but I am doing something wrong and I am not finding the error. I think it should be obvious, but I am blind.
w = 1/2 (4 - x)^2; divisions = 20; CargDist = Plot[ w, {x, 0, 4}, PlotStyle -> Red, PlotRange -> {{-.25, 4}, {-1.5, 8}}, Epilog -> {Thickness[.004], Arrowheads[#]& /@ Subdivide [0.04, .02, divisions], Arrow[({{#1, (1/2)(4 - #1)^2}, {#1, 0}}&) /@ Subdivide[0, 3.2, divisions]], EdgeForm[Thick], Opacity[0.2], Gray, Rectangle[{0, -1}, {4, 0}]}] 
