Solution

After a pleasant showering, a water droplet of mass $1.2 \times 10^{-11}\,\mathrm{kg}$ is located in the air near the ground. An atmospheric electric field of magnitude $6.0 \times 10^{3}\,\mathrm{N\,C^{-1}}$ points vertically downward in the vicinity of the water droplet. The droplet remains suspended at rest in the air. Find the electric charge on the droplet.