A fish tank has dimensions 36 cm wide by 1.0 m long by 0.60 m high. If the filter should process all the water in the tank once every 4.0 h, what should the flow speed be in the 3.0-cm-diameter input tube for the filter?

0.02 m/s

Explanation:

using the formula for flow rate

Q = V / t = Av

v (speed) = V / (TA) where V is volume in m³, t is in seconds, and A is area of the 3.0 cm diameter

V = length * breath * height = 0.36 m * 1.0 m * 0.60 m = 0.216 m³

Area = πr² = π (0.03 / 2) ² = 0.00071 m²

t = 4 * 60 * 60 = 14400 s

substitute the values into the equation

v = 0.216 m³ / (14400 s * 0.00071 m²) = 0.02 m/s