Sorry about that! I've added the code from Stack Exchange to this post.
As for the speed and memory consumption, generating the plot takes me about 94 seconds and uses about 12MB of RAM:
AbsoluteTiming[MaxMemoryUsed[Plot[posiçãoVal[?], {?, 0, 2?}, PlotRange -> {15, 66}]]]
{94.1281, 11679216}
Adding the option PerformanceGoal -> "Speed"
improves things in a noticeable way and does not seem to make the plots appear any different. I've gone ahead and added that option in the post. On my machine, it's now about 18 seconds and 3MB of RAM:
AbsoluteTiming[MaxMemoryUsed[Plot[posiçãoVal[?], {?, 0, 2?}, PlotRange -> {15, 66},
PerformanceGoal -> "Speed"]]]
{18.4705, 2907720}
Let me know if you're still having issues.