Answer:
Increases by a factor of 16
Explanation:
Mass flow is conserved. Since liquids are practically incompressible (constant density), we can say that the volume flow is also conserved. Volume flow is equal to the velocity times the cross sectional area. For a round pipe, the cross sectional area is one fourth pi times the square of the diameter.
V₁ = V₂
v₁A₁ = v₂A₂
v₁ (¼ π D²) = v₂ (¼ π (D/4)²)
v₁ D² = v₂ (D/4)²
v₁ D² = v₂ D² / 16
v₂ = 16v₁
The speed increases by a factor of 16.
