What is the mass of the sphere?

[dannie]

Homework Statement

Two large , horizontal charged plates are separated by 0.050m. A small plstic sphere is stationary and suspended between them and is experiencing an electric force of 4.5x10^-15 N.
What is the mass of the sphere?

F=ma

My attempt.

F=4.5x10^-15N
a=9.8m/s^2
m=4.5x10^-15 N/9.8^2
=4.59x10^-16kg

 

[darkxponent]

looks correct. But use 'g' instead of 'a' as sphere is at rest.

 

[collinsmark]

Deleted post. I completely misread the problem.