© February 2007
In 1911 Robert Milikan set out to try and determine the charge of electron. He did this by balancing charged oil droplets in an electric field, using an equipment sililarly with the one shown below.
Two forces govern the movement.
Coulomb force (qV/d)
Newton force (mg)
q = droplet charge;
V = voltage between plates;
d = distance between plates;
m = droplet mass;
g = let's take as standard gravity
Using the following interface, you can compute one out of five parameters necessary to drops stop moving. Leave blank one of.