There are many parallels between gravitational phenomena and electrical phenomena: One can think of a test object with mass in a gravitational field as analogous to a test object with positive charge in an electric field.

(a) Draw the gravitational field line pattern for the EarthMoon system, showing arrows on the lines to indicate direction.

(b) Now consider a system made up of two charged objects. Which type of charge (positive or negative) must each object carry in order to have an electric field line pattern match the gravitational field line pattern that you drew in part \(a\) ?

(c) Do you see any differences between electrical and gravitational phenomena?