Water stands upto a height `h` behind the vertical wall of a dam what is the net horizontal force pushing the dam down by the stream if width of the dam is `sigma`? `(rho=` density of water)
A. `2hsigmag`
B. `(h^(2)sigmarhog)/(2)`
C. `(h^(2)sigmarhog)/(4)`
D. `(hsigmarhog)/(4)`
