all right. So, we will get back to this c theta part this is from here only I can tell
tell me ask this question if I were to trim the ship by an angle theta what is my restoring moment what is the moment that is trying to bring it back what is the. So, called pitch you know what I should say in case of trim the trimming moment. See it is given by weight into g z in longitudinal direction or I can say g m l into theta actually because in in pitch axis theta is always small. So, we always write that way in reality and you have seen the trim cannot be more than two three degrees because if it was so the bow would have come up. So, trim is always very small. So, it is w into weight into gm l into theta this is my trimming moment m right that is what we have done always you know if we shift a weight here what happen w into d equal to w g m l theta and this gm l you write as you know T p c etcetera etcetera not T p c sorry m c T moment we change trim. So, but our case it is like that. So, what is w it is I always prefer to use this in a s i unit s i unit mean its force into distance force meaning mass into acceleration. So, therefore, what I do is I will write now mass sometime you know people write trimming moment as confusion be always have tan meter actually it is TransForce meter. So, it is always good not use consistent s i unit. So, I prefer to write this as rho g v because there is no ambiguity if you write this as rho g into sometime you know people do not take g etcetera. So, if you use that this becomes fully consistent mu tan rho no confusion it is mass by length cube g no confusion this no confusion. So, this into g m l into theta this is my c theta what it means is that if I were to just like in heave if I were to trim it or pitch it by theta degree there is a moment trying to restore that of this amount if I once again if I trim a hull like this if trim a hull like this the moment comes in trying to restore it back and that is given by this into theta larger linear with respect to theta and therefore, this is my. As you know very well for estimate purpose for ship sometime I can use g m l equal to b m l you know approximately, but that is for ship we do not have to do it, but this is my best formula. So, this g m l is known now we will get back to again this this part lets again have an estimate I x x I y y etcetera first of all let’s look at I y y you see here this is
ก็ได้ ดังนั้น เราจะกลับไปส่วนทีตา c นี้เป็นจากที่นี่เท่านั้นฉันสามารถบอกtell me ask this question if I were to trim the ship by an angle theta what is my restoring moment what is the moment that is trying to bring it back what is the. So, called pitch you know what I should say in case of trim the trimming moment. See it is given by weight into g z in longitudinal direction or I can say g m l into theta actually because in in pitch axis theta is always small. So, we always write that way in reality and you have seen the trim cannot be more than two three degrees because if it was so the bow would have come up. So, trim is always very small. So, it is w into weight into gm l into theta this is my trimming moment m right that is what we have done always you know if we shift a weight here what happen w into d equal to w g m l theta and this gm l you write as you know T p c etcetera etcetera not T p c sorry m c T moment we change trim. So, but our case it is like that. So, what is w it is I always prefer to use this in a s i unit s i unit mean its force into distance force meaning mass into acceleration. So, therefore, what I do is I will write now mass sometime you know people write trimming moment as confusion be always have tan meter actually it is TransForce meter. So, it is always good not use consistent s i unit. So, I prefer to write this as rho g v because there is no ambiguity if you write this as rho g into sometime you know people do not take g etcetera. So, if you use that this becomes fully consistent mu tan rho no confusion it is mass by length cube g no confusion this no confusion. So, this into g m l into theta this is my c theta what it means is that if I were to just like in heave if I were to trim it or pitch it by theta degree there is a moment trying to restore that of this amount if I once again if I trim a hull like this if trim a hull like this the moment comes in trying to restore it back and that is given by this into theta larger linear with respect to theta and therefore, this is my. As you know very well for estimate purpose for ship sometime I can use g m l equal to b m l you know approximately, but that is for ship we do not have to do it, but this is my best formula. So, this g m l is known now we will get back to again this this part lets again have an estimate I x x I y y etcetera first of all let’s look at I y y you see here this is
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