So, the moment here I can write - moment of that equal to n into… in fact, moment on the stock - let me call it rudder stock - into e minus a; this is important sometimes because this moment that comes is the moment…. you have got a rudder and you have got a steering gear machine that you have to turn; it has to turn against that kind of moment; you are turning this rudder about this point like this and the moment that you need - if you have turned so much, the moment that is coming on that is so much; therefore, you need to… that moment… because that much of moment you have to apply; this is necessary for your steering gear design - that is why you need that.
Why I am saying that is because in the rudder design we will find out that essentially if you can estimate this l etcetera from every section you can integrate and then get the