Tension of strings and gravity force help

[Pear_Head]

Homework Statement

Q= 2800N
G= 10m/s^2
s=35m
t=10s
__________
Fst=? (st-String tension)

Can anyone help me with this, i have a test tomorrow
And if anyone can give me the formula for the Tension force i'd be really grateful.

 

[cupid.callin]

please specify the condition properly
is the charges hanged through string?
any electric field?
mass of particle?
and what is 35m?