Physics — Free-body: top of a vertical loop
At the top, gravity and the track both point to the centre.
Make it your own.
title "Cart at the top of a vertical loop"
body C at 360,260 size 120,80 label "cart"
force W on C vector 0,150 color red label "mg"
force N on C vector 0,120 color blue label "N (track, downward)"