Suppose you have a friend who has a part-time job translating computer maintenance training materials from Japanese into English. A section of a manual for an inkjet printer is missing, and an important derivation is needed. The printer works by steering drops with charge q and mass {rm m} between two parallel surfaces where there is a uniform electric field E that deflects them the appropriate amount (see the figure). The field extends over the length {rm L} and width d. The reader of the manual must know the minimum speed of the drop if it is to make it through the electric field region without hitting either of the plates. Find this minimum speed.