Answer to Question #161945 in Physics for Jack

Question

calculate the electric field at the detector from the cloud (remember electric field is vector!) and draw in what the electric field arrow would look like on the picture.

Answer 1

Assume the cloud is at distance d from the detector and carries charge Q. The field would be

$$E=\frac{kq}{d^2}.$$

Depending on sign of the charge, the field from a positively charged cloud would be directed toward the detector, otherwise, the field would be directed from the detector to the cloud.