What Electric Field Magnitude Is Needed to Reverse an Oil Drop's Motion?

[lch20yy]

Homework Statement

an oil drop carries six electronic charges, has a mass of 1.6 x 10^-12 g, has a mass of 1.6 X10^-12g, and falls with a terminal velocity in air. what magnitude of vertical electric field is required to make the drop move upward with the same speed as it was formerly moving downward?

Homework Equations

E=F/Q

The Attempt at a Solution

what i did is multiply mass by g, gives the electric force, and then divided by the charges.am i doing it right?

 

[Spinnor]

See,

http://www.antonine-education.co.uk/physics_a2/options/Module_8/Topic_2/topic_2.htm

and,