Hey all,

I have this problem and I cannot for the life of me figure out what I'm doing wrong that the homework isn't accepting my answer. Can someone take a look at what I'm doing and maybe tell me whats wrong? Problem is below:

A rectangular tank is http://www.ilrn.com/ilrn/formulaImag...+m+%5C%3A&ns=0 wide and http://www.ilrn.com/ilrn/formulaImag...+m+%5C%3A&ns=0 deep. If the tank is only half full with water, find the force against one end of the tank.

(Recall that http://www.ilrn.com/ilrn/formulaImag...%7D%5C%2C&ns=0 = http://www.ilrn.com/ilrn/formulaImag...%7D%5C%2C&ns=0.)

F = ______wN

Pressure on Strip: (6-y)w

Area of Strip: 13dy

Force against strip: (6-y)*13dy = 13w(6-y)dy

F = Integral from 0-3 {13w(6-y)dy}

13w(6y-y^2/2)dy

13w(18-9/2)

13(27/2) =351/2

I've tried entering my answer in as a decimal and as the exact answer and for some reason its telling me it is incorrect. Any help would be great.