Answer :
The exit velocity of water is B. 15 m/s.
According to equation of continuity, for a steady flow of water, the volume of liquid entering a pipe in 1 second is equal to the volume that leaves per second.
If the initial exit area of the pipe is A₁ and the speed of exit is v₁ and the final exit area is A₂ and its corresponding exit velocity is v₂, then,
[tex] A_1v_1 = A_2v_2 [/tex]
Rewrite the expression for v₂.
[tex] v_2 =(\frac{A_1}{A_2} )(v_1) [/tex]
Substitute 10 cm² for A₁, 2 cm² for A₂ and 3 m/s for v₁.
[tex] v_2 =(\frac{A_1}{A_2} )(v_1) =\frac{10 cm^2}{2 cm^2} (3m/s) =15 m/s [/tex]
The exit speed of water from the hose is 15 m/s.