Final answer:
The hydrostatic force against one side of the plate can be expressed as an integral and evaluated to approximately 50 units.
Step-by-step explanation:
The hydrostatic force against one side of the plate can be expressed as an integral using the formula F = ∫(0 to h) ρgx dA, where ρ is the density of water, g is the acceleration due to gravity, h is the height of the submerged portion of the triangle, and dA is the differential area of the submerged portion. In this case, the height of the triangle is 5 m and the base is 4 m.
Using the formula and integrating, the integral would be ∫(0 to 5) 4x dx, where x represents the distance from the base of the triangle to the height.
Evaluating this integral gives us ∫(0 to 5) 4x dx = [2x^2] from 0 to 5 = 2(5^2) - 2(0^2) = 50. Therefore, the hydrostatic force against one side of the triangle is approximately 50 units.