How much change in position of the laser spot resulted from the 50 milligram mass added to the plates with no voltage. What force in newtons does the weight of this 50 mg mass exert on the plates? Use that to nd the force in newtons of the attraction of the two plates just at that point of instability. The deflection is proportional to the force. How far apart were the plates at the moment they started to accelerate toward one another? You can get that from knowing the position of the laser spot when the plates were in contact, and then where it was when the voltage was applied. The spot moves in proportion to the change in the angle, which is zero when they are in contact. We would have a change of the plate tip angle which is half the measured change in the light beam because the reection at the mirror doubles the deection of the laser beam. If the distance the beam moves is y, then the angle that separates the plates is 9 = ylL where L is the distance from the mirror to the vertical meter stick that the light beam strikes. Near the beginning of the video we measured L=1.45 m. The actual separation of the plates at this moment is d=exs where S is the distance from the fulcrum to the center of the plates which you noted in an earlier question. Now you know the separation of the plates, the voltage on them and the force exerted on the upper one by its attraction to the lower one. What was that force in newtons? How far apart were they? When you respond to this part, explain your work so that we can comment on it and guide you if you are having a problem with it