Two parallel plates have a potential difference between them. the distance between the plates is halved, but the electric field between them remains constant. how did the potential difference change? a. potential difference was halved. b. potential difference did not change. c. potential difference was doubled. d. potential difference was quadrupled.

A5 foot by 5 foot box culvert is buried 6 feet beneath the surface of the ground. a crosssection of this very long culvert (into and out of the page) is illustrated below. assume that the soil in which the culvert is buried has the following properties: jt = 120 pcf, w = 12%, ko = 0.50, ka = 0.33, and kp = 3.00. calculate the total horizontal force per unit length of culvert (fh) felt on one of the vertical faces of the culvert.