A `16cm^(3)` of water flows per second through a capillary tube of radius r cm and of length 1cm, when connected to a 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))/(8etal_(1))andV_(2)=(piP_(2)r_(2)^(4))/(8etal_(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))xx(l)/(l)=((1)/(2))^(4)=(1)/(16)`
`V_(2)=(16)/(16)=1cm^(3)//s`,
volume of water flowing per minute = `1xx60xx60cm^(3)//min`
`therefore` Mass of water flowing per minute
`=60xx1=60` gram/min.