Answer:
367.43 mm²
Explanation:
Given:
Flow rate, Q = 0.7 L/s
1000 L = 1 m³ = 10⁹ mm³
thus,
1 L = 10⁶ mm³
Therefore,
Q = 0.7 × 10⁶ mm³/s
Cross-sectional area at the top of the sprue = 750 mm²
Length of the sprue = 185 mm
Now,
Velocity =
where, g is the acceleration due to gravity = 9.81 m/s²
h is the height through which flow is taking place = 185 mm = 0.185
thus,
Velocity =
or
velocity = 1.9051 m/s = 1905.1 mm/s
Also,
Q = Area × Velocity
thus,
0.7 × 10⁶ = Area × 1905.1
or
Area = 367.43 mm²