Electrostatics and current Web sites

Here is the link for the sites we used in  computer labs last week:
http://www.hazelwood.k12.mo.us/~grichert/sciweb/electric.htm

[AP students look over the circuits links, you probably need the practice and then go back and do the electrostatics]

All students go to the electrostatics physlets and do all 4 but present the solution for number 4 (find the mass of the particle) explaining how you did it. For AP its 20 points extra credit. For honors it is an assignment and it will replace your lowest lab grade from other labs. For mathematical it is all that plus 30 points of extra credit. Try to solve it on your own. If you can't, here are some hints, but don't read them all at once. Try solving it with as few hints as possible. Q is given in the text.

The time is given ( note it is in milliseconds). The location is given  in yellow when you click on a position. The field, E,  is .5 N/C where ever the stripes are shown and zero elsewhere. The difference between the kinetic energy before and after the field = M/2( vi squared - vf squared) the field is equal to work done by the field. This work  is force x distance = Q E dist. Write this as an equation, then manipulate the quantities and come up with an equation for M.

You can find dist by clicking on the first line and then the last line and noting the change in location. You can find vi by putting the particle  before the field by  clicking on the particle, noting x and t, then by starting and pausing again before it enters the field and noting x and t again. You now know delta x and delta t before the field, so you can find vi.  You can do the same after the field.