Froude number was titled after William Froude is a dimensionless number known as the ratio of characteristic velocity to the gravity wave velocity.

$Froude Number Formula -1$

Where the characteristic velocity is v and

the characteristic wave velocity is c,

gravity in terms of the Froude number is articulated as,

$Froude Number Formula -2$

Where,

It is used to determine the resistance of a partially moving body that is immersed in water.

Underneath are some of the solved problems based on Froude Number:

Problem 1: Find the Froude number if the boat’s length is 5 m and the velocity is 20 m / s.

Answer:

Known: length l = 5m,

velocity v = 20 m/s

The Froude number is articulated as,

\begin{array}{l} F_{r} = \frac{v}{{(g l)}^{\frac{1}{2}}} \end{array}

\begin{array}{l} F_{r} = \frac{20}{{(9.8 \times 5)}^{\frac{1}{2}}} \end{array}

\begin{array}{l} F_{r} = \frac{20}{4.427} \end{array}

F_r = 2.86

Thus, the Froude number of the boat is 2.86.

Problem 2: Calculate the velocity of the fish moving through the water if its length 0.3 m and Froude number is 0.9.

Answer:
Known: l (length) = 0.3m

Fr (Froude number) = 0.9

The Froude number is given by,

\begin{array}{l} F_{r} = \frac{v}{{(g l)}^{\frac{1}{2}}} \end{array}

The velocity of the moving fish is

v= F_r × (gl)^(1/2)

v = 0.9 × (9.8 × 0.3)^(0.5)

v = 0.9 × 1.71

v = 1.539 m/s

Thus, the velocity of the moving fish is 1.59 m/s.

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