Question

A body having a net charge of 30C is placed in a uniform electric field of 800N/C directed vertically. What is the mass of this body if it lies on the surface in the field?

Answer 1

First, find the force:

$$F=qE=30·800=24000\text{ N}.$$

Assuming the experiment is conducted on Earth, the mass is

$$m=\frac Fg=2449\text{ kg}.$$