The cylindrical tube of a spray pump has a cross-section of `8 cm^2`, one end of which has `40` fine holes each of area `10^-8 m^2`. If the liquid flows inside the tube with a speed of `0.15 m min^-1`, the speed with which the liquid is ejected through the holes is.

Options

A. `50 ms^(-1)`
B. `5 ms^(-1)`
C. `0.05 ms^(-1)`
D. `0.5 ms^(-1)`

Answer

B

Explanation

According to equation of continuity, (area A) `xx` (velocity v) = constant
`:.` For tube, `(8 xx 10^(-4)) xx ((0.15)/(60)) = A_(1)v_(1)`
For holes, `(40 xx 10^(-8)) xx v= A_(2)v_(2)`
As `A_(2) v_(2) = A_(1) v_(1)`
`:. 40 xx 10^(-8) xx v = (8 xx 10^(-4) xx 0.15)/(60)`
or `v= (8 xx 10^(-4) xx 0.15)/(40 xx 10^(-8) xx 60) = (8 xx 15)/(4 xx 6) = 5ms^(-1)`