An opentopped tank with diameter D is filled with a liquid w
     An open-topped tank with diameter D is filled with a liquid with density rho and viscosity mu to a height h. Under the influence of gravity g, the tank is drained through a hole with diameter d. Using dimensional analysis, find the time t it takes to empty the tank. 
  
  Solution
t =time
d = dia o fhole
D dia of tank
h initial ht
rho density
mu viscosity
D dia
g gravitational const
let t = fn( d,v,h,rho,mu,D,g)
get groups ( rho V3)(/mu g)
(t mu)/(rho d2)
Vo/d3 , ho/d D/d
t mu/(rho d2 ) = fn( length1/length2, --, )

