Question

A test charge of +3.00 10-6 C experiences a downward electrostatic force of 11 N when placed at a certain point in space. What are the magnitude and direction of the electric field at this point?
drwls
The field direction is down and the field strength is 11/3*10^-6 = 3.7*10^6 N/C (or volts/meter)

This is close to the field strength that casues air breakdoown.