Give density of water in fluid force problem

The solution assumes that we use a density of 1000 kg/m^3, but this
wasn't explicitly given.

Author: d-torrance

OpenProblemLibrary/Michigan/Chap8Sec5/Q27.pg

@@ -61,7 +61,7 @@ BEGIN_TEXT
 Set up and calculate a definite integral giving the total force on
 the dam shown in the figure below, if the width \(w = $wid\) m, height
 \(h = $hei\) m, and base width \(b = $bas\) m, which are approximately
-the dimensions of the Aswan Dam in Egypt. Use \(g=9.8\hbox{ m/s}^2\).
+the dimensions of the Aswan Dam in Egypt. Use \(\rho=1000\hbox{ kg/m}^3\) and \(g=9.8\hbox{ m/s}^2\).
 
 $PAR
 $BCENTER