Quote:
Originally Posted by joegrundman
this still not correct physics, either 
innit, and the difference is in fact vanishingly small except at very close ranges. with sine you are measuring range to top of mast, with tangent you measure range to waterline.
e.g 25m mast subtends 1 degree
range to mast top (using sin) = 1432.47m
range to waterline (using tan) = 1432.25 m
a difference of 22 cm
e.g. 25 m mast subtends 10 degrees
range to masttop (using sin) = 143.97m
range to waterline (using tan) = 141.78m
a difference of just over 2 m, and in either case within minimum torpedo range.
Using sine is more practical for the simple reason that the same circular sliderule can be used to solve this calculation as for all the other sine-based calculations you may need to solve! |
Oooooh my aching head! 
It is waaay too early in the morning for this.
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