Write the equation of continaity.

Explanation

`a_(1), v_(1), =a_(2), v_(2)`, for a stream line flow whers `a_(1), a_(2),` represent areas of cross section at two ends and `v_(1) and v_(2)` speeds at two ends of a tube of flow.
`i.e, ((pid_(1)^(2))/(4)) v_(1)=((pid_(2)^(2))/(4))v_(2)`
`i.e, d_(1)^(2)v_(1)=d_(2)^(2)v_(2)`