Water is flowing continuously from a tap having an internal diameter `8xx10^(-3)`m. The water velocity as it leves the tap is `0.4 ms^(-1)`. The diameter of the water stream at a distance `2xx10^(-1)`m below the tap is close to `(g=10m//s^(2))`

Explanation

`v_(2)^(2) = v_(1)^(2) + 2 gh = (0.4)^2 + 2 xx 10 xx 0.2 = 4.16`
`v_2 = sqrt(4.16) = 2.04 m//s`
`a_1 v_1 = a_2 v_2`
`(pi d_1^2)/(4) v_1 = (pi d_2^2)/(4) v_2 ` (because d : diameter)
`d_2 = d_1 sqrt((v_1)/(v_2))`
=`8 xx 10^-3 sqrt((0.4)/(2.04)) = 3.54 xx 10^-3 m`.
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