- #1
boileroo
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Homework Statement
I am having trouble understanding problems involving the force and bending moment on a submerged surface.
The problem in question is as follows:
variation in density of a muddy lake is given as rho = rhoo + kh, where rhoo = 1000, k = 100 and h = depth of lake.
A vertical plate is used as a dam, and the depth of the water is 10m.
Find the force/meter width and moment/meter width.
My problem lies in part b, calculating the moment
The Attempt at a Solution
F = int(rho*g*y) dy = int((rhoo +kh)*g*y) dy = (rhoo*g*h2)/2 + (k*g*h3)/3 = 815.5x103 N
It is this next part with the moment I am struggling on. The formula i have been taught to use is:
M = int(r*P) dA
I think that this goes to M = int((rhoo +kh)(y-h) dy but am unsure why, if it is infact it is the case.
Any help would be appreciated!