This applet shows the static equilibrium conditions for seesaw:
Net force and net torque must be zero.
If you change the angle of the seesaw, the net potential energy is kept constant,too.

---

Enjoy the fun of Physics! You can access this simulation online from
static equilibrium condition for seesaw
Designed by Fu-Kwun Hwang (http://www.phy.ntnu.edu.tw/ntnujava/)
Deptartment of Physics, National Taiwan Normal University, Taiwan