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Q5. The force acting normal to the centerline plane of a rudder is given by the expression:

F_n = 15.5 A V² α newtons

Where: A = rudder area (m²)

v = ship speed (m/s)

α = rudder helm angle (degrees)

A ship travelling at a speed of 20 knots has a rudder configuration as shown in Fig Q4. The center of effort for areas A₁ and A₂ are 32% of the width from their respective leading edges. The rudder angle is limited to 35º from the ship's centerline.

Calculate EACH of the following:

(a) The diameter of the rudder stock required for a maximum allowable stress of 77 MN/m²;

(b) The drag component of the rudder force when the rudder is put hard over at full speed.