Take the vertex as the coordinate origin, and the upward direction is the positive direction of Y axis.

The equation of the edge is y=3x/2, then x=2y/3.

f = 2∫(0-& gt； 3)ρg(h-y)2y/3dy

= 4ρg/3∫(0-& gt； 3)(3-y) years

=6ρg

=60000 Newton