Calculation of Resultant force of a plate at the bottom of water

Problem: Find the resultant force on one side of 25 cm diameter vertical circular plate standing at the bottom of 3m pool of water? Density of water =1000 kg/m³, g=9.81 m/s²
Exam Name: Sylhet Gas Field Ltd. 2017

Solution:
Resultant force,
                        P=૪ЋA
 Here, ૪= 9.81 KN/m³
             = 9.81 х 10³ N/m³
       
            Ћ = (3+ 2.975)/2
                = 2.9875

            A= πd²/4
               = (π * 0.25²)/4
               = 0.0491 m²
                 =4.9 х 10 ^-4 m²


   ∴P=૪ЋA
       = 9.81 х 10³  * 2.9875 * 0.0491
       = 1438 N

Answer: 1438 N

---