Answer:
m = 1,429 10⁻⁴ kg
Explanation:
For the object to remain floating, the translational equilibrium condition must be met, we set a reference system where the vertical upward direction is positive
F_e -W = 0
F_e = W
q E = m g
we clear
m = [tex]\frac{qE}{g}[/tex]
let's calculate
m = [tex]\frac{7 \ 10^{-6} \ 200}{ 7 }[/tex]
m = 1,429 10⁻⁴ kg
