SSC JE Mechanical Engineering 25-Sep-2019 Shift 1 Paper

Force on the dam wall (F) = Pressure at the center (P) × Projected area of the dam (A) = ρgAx̅
The pressure at the center (P) = ρ × g × x̅
Given:
Height of the dam (H) = 20 m
Height of the centroid from the water surface (x̅) = H/2 = 10 m
Density of water (ρ) = 1000 kg/m‌3
Width of dam (w) = 25 m
Area of dam (A) = 20 × 25 = 500 m‌2
F=P×A=(ρ×g×h̅) × 500 = (5 × 106 × g) = 5g MN