analogy to electric field: wind the point of this tutorial is to introduce electric fields. but instead of doing so immediately, we'll start with an analogy to wind. a. an industrial-strength fan creates the wind pattern indicated in this diagram. someone holds a small kite at point a. then the person holds a larger kite at that same point. in both cases, the kite directly faces the fan and therefore catches the wind. in what sense is the wind stronger on the large kite than it is on the small kite? 1. 2. in what sense is the wind equally strong at both kites? 3. a student says, the wind itself is equally strong at point a no matter which kite you hold there-or even if you don't hold a kite there. the large kite feels more force than the small kite because it has more area and therefore catches more wind, not because the wind itself is stronger. does this student agree with the answers you just gave? if not, do you think the student makes good points? in what ways do you disagree? as a convenient catchphrase, let's define the wind field as the strength and direction of the wind itself at a given point (whether or not an object is held there). so, according to the student, the wind field at point a stays the same whichever kite you put there; but that same wind field produces a different wind force on kites of different sizes.