4-1- Forces on a Consider the forces exerted by the water on the cylindrical dam below Palm:0 D do r4m B P (M) proths ds rdeb dF = egz(m) brdo) Numerical data : dF = egbr? cos8 do z10) = rosd (w) z Figure 5 2(e) -> -> The density of fresh water is 1000 kg/ m The length of the dam, normal to the plane of the figure, is b=30m caso Sin o do = 1) a) - Find the expression of the elemental force exerted by the water at any point on the surface of the dam (polar coordinates might be useful). -4 (-1-1] - 2 b) Find the sum and moment of the corresponding wrench. c) - What is the nature of this wrench? /2 os? do e) - Find the central axis of the wrench. Is(It cas 28) de /2 Sin 28 16