i downloaded the XML file but it is missing the slider m values inside the slider
i debugged by copying the setting in the m slider from the m1 and m2 sliders.
i attached the 3 attachments/evidence for your consideration to ask this question "is there a bug ?"
i also attached the fixed XML for you :)
by the way, the applet is pedagogically wonderful and it works on the web. Excellent work
i used to refer to Equilibrium of Three Forces http://www.walter-fendt.de/ph14e/equilibrium.htm
but now i will remix yours :)