A `16cm^(3)` of water flows per second through a capillary tube of radius r cm and of length 1 cm, when connected to pressure head of h cm of water. If a tube of the same length and radius `r//2` is connected to the same pressure head, find the mass of water flowing per minute through the tube.

Explanation

`V_(1)=(piP_(1)r_(1)^(4))/(8 eta l_(1))` and `V_(2)=(piP_(2)r_(2)^(4))/(8 eta l_(2))`
`(V_(2))/(V_(1))=(P_(2))/(P_(1))xx(r_(2)^(4))/(r_(1)^(4))xx(l_(1))/(l_(2))=((r//2)^(4))/(r^(4))=l/l=(1/2)^(4)=1/16`
`V_(2)=16/16=1cm^(3)//s`
Volume of water flow per minute `=1xx60=60cm^(3)` /min
`:.` Mass of water flowing per minute
`=60xx1=60` gram /min