The reading of a barometer fitted with a closed pipe is `3.5 xx 10^(5) Nm^(-3)`. When the valve ef the pipe is opened, the pressure read by barometer reduces to `3.0 xx 10^(5)Nm^(-2)`. Calculate the velocity of flow of water in the pipe.

Options

A. 10 m/s
B. 20 m/s
C. 30 m/s
D. 40 m/s

Answer

A

Explanation

According to Bernoulli.s theorem,
`(P_(1))/p+1/2v_(1)^(2)=(P_(2))/p+1/2v_(2)^(2)`
`(3.5xx10^(5))/(10^(3))+0=(3xx10^(5))/(10^(3))+1/2v_(2)^(2)`
`350-300=1/2v_(2)^(2)`
`v_(2)^(2)=50xx2=100`
`v_(2)=10m//s`
So the correct choice is (a).