The basic mechanism behind how an inkjet printer operates is that drops of ink, each with a radius of r$=20\backslash$mu m$,$ are charged to q$=1\mathrm{.}3\backslash$times $1013$ C and sprayed from a nozzle towards the page at an initial speed of $20$ m$/$s$.$ On the way to the paper, they pass a region with a uniform electric field of magnitude E$=|$E$|$ between two charged plates which deflects them up or down. Assume that the distance from the centre of the plates to the paper is d$=2\mathrm{.}0$ cm$.$ The maximum height of a letter is $6$ mm$,$ i$.$e$.$ the drops have to be deflected up or down $3$ mm$.$ What is the maximum electric field strength needed? Start by sketching the situation. Note that there is one piece of information that you will have to estimate.