I hope the following is what you want. (I do not know what you want with the balance, just to see it tilted when it is not balanced?)

Ckick [b]measure[/b] checkbox and drag the slider to change mass to see it un-balanced.

/htdocs/ntnujava/ejsuser/2/users/ntnu/fkh/massbalance_pkg/massbalance.propertiesFull screen applet or Problem viewing java?Add http://www.phy.ntnu.edu.tw/ to exception site list
Press the Alt key and the left mouse button to drag the applet off the browser and onto the desktop. This work is licensed under a Creative Commons Attribution 2.5 Taiwan License
Download EJS jar file(1296.4kB):double click downloaded file to run it. (3 times by 3 users) , Download EJS source (1 times by 1 users) View EJS source