posted by Stephanie22-41 .
A charged cloud system produces an electric field in the air near Earth's surface. A particle of charge -2.1 x 10-9 C is acted on by a downward electrostatic force of 4.3 x 10-6 N when placed in this field. (a) What is the magnitude of the electric field? (b) What is the magnitude of the electrostatic force on a proton placed in this field? (c) What is the gravitational force on the proton? (d) What is the ratio of the electrostatic force to the gravitational force in this case?