Answer:
v₂ = 16 m/s
Explanation:
We can use the continuity equation, which is as follows:
[tex]A_1v_1 = A_2v_2\\[/tex]
where,
A₁ = Area of inlet = πd²/4
A₂ = Area of outlet = π(d/2)²/4 = πd²/16
v₁ = velocity at inlet = 4 m/s
v₂ = velocity at outlet = ?
Therefore,
[tex](\frac{\pi d^2}{4})(4\ m/s)=(\frac{\pi d^2}{16})v_2\\\\[/tex]
v₂ = 16 m/s