The electric field between the plates of a parallel-plate capacitor is horizontal, uniform, and has a magnitude E. A small object with a charge of -2.12
is attached to the string. The tension in the string is 0.310 
, and the angle it makes with the vertical is 12 
.What is the mass of the object?
What is the magnitude of the electric field?
Not sure where to even begin here.... help?
