Daily License Questions about Ship Stability and Trim: I just think people need to have some knowledge in their heads, professional or otherwise. After 2007 our world has changed due to the advent of Smart Phones. Retaining knowledge is like being able to play a musical instrument, if you do not use it you will lose it! The questions I post with will hopefully help you keep what you already know or remind you of what you should know. William E. George
???? A lot of these questions seem to be B. Better to guess than not answer on a USCG license exam.
ReplyDeleteGood Day from Australia,
ReplyDeleteI have a stability question, perhaps you can help?
"A vessel's resistance to pitching is greater than it's resistance to rolling" Justify this statement using concepts of inertia.
Best Regards, David Langbecker
Resistance to pitching can be measured by the vessel's Longitidinal GM which is much greater than it's Transverse GM due to a much greater value for Longitudinal KM.
DeleteComparing both longitudinal and transverse KB are virtually the same, but their BMs are much different due to their moments of inertia or BM, mecentric radius.
BM = I/Displaced Volume
Where I =Moment of Inertia
For transverse I of a rectangular barge
I = lb^3/diaplaved volume
However for longitudinal I of s rectangular barge
I =bl^3/displaced volume
For both:
l = length
b= beam
Resistance to pitching can be measured by the vessel's Longitidinal GM which is much greater than it's Transverse GM due to a much greater value for Longitudinal KM.
ReplyDeleteComparing both longitudinal and transverse KB are virtually the same, but their BMs are much different due to their moments of inertia or BM, mecentric radius.
BM = I/Displaced Volume
Where I =Moment of Inertia
For transverse I of a rectangular barge
I = lb^3/diaplaved volume
However for longitudinal I of s rectangular barge
I =bl^3/displaced volume
For both:
l = length
b= beam