we know that a spherical ball falling in a fluid is acted by viscous force calculated by Stoke's law...
but how to calculate the viscous force on and terminal velocity of a square sheet or cube falling/moving in a fluid medium ,for instance say a square sheet (or cube) of iron ( or something dense) is falling inside sea from say a ship, such that its flat surface is parallel to sea surface when it enters the liquid?

Question

we know that a spherical ball falling in a fluid is acted by viscous force calculated by Stoke's law...
 but how to calculate the viscous force on and terminal velocity of a square sheet or cube falling/moving in a fluid medium ,for instance say a square sheet (or cube) of iron ( or something dense) is falling inside sea from say a ship, such that its flat surface is parallel to sea surface when it enters the liquid?

ujjwal · Answer

This might help: http://books.google.com.np/books?id=XjNS6v7q130C&pg=PA61&lpg=PA61&dq=Viscous+force+for+a+cube&source=bl&ots=sHkzQEPyg7&sig=3VFmE1DPyaBukV_kHo8IhIHi9Vo&hl=en&sa=X&ei=jusSULGeFcWsrAeFrYGoAw&sqi=2&redir_esc=y#v=onepage&q=Viscous%20force%20for%20a%20cube&f=false

ujjwal · Answer

And this one seems to be more helpful: http://books.google.com.np/books?id=YWciuG0SGcEC&pg=PA91&lpg=PA91&dq=Viscous+force+for+a+cube&source=bl&ots=RrtJDICr7s&sig=K3hP0UJcz-R6_YG9Es8Tu9Kneeo&hl=en&sa=X&ei=jusSULGeFcWsrAeFrYGoAw&sqi=2&redir_esc=y#v=onepage&q=Viscous%20force%20for%20a%20cube&f=false