A rectangular dam is $40$ ft high and $60$ ft wide. Assume the weight density of water is $62\mathrm{.}5$ lbs$/$ft$3.$

Find the work required to pump all the water out of the cylinder in the preceding exercise if the cylinder is only half full. $247.[$T$]$ A rectangular dam is $40$ ft high and $60$ ft wide. Assume the weight density of water is $\backslash (62\mathrm{.}5\backslash$mathrm$\{$lbs$\}/\backslash$mathrm$\{$ft$\}\{\}^\{3\}\backslash ).$ Compute the total force $\backslash ($ F $\backslash )$ on the dam when

a$.$ the surface of the water is at the top of the dam and

b$.$ the surface of the water is halfway down the dam.

$248.[$T$]$ Find the work required to pump all the water out of a cylinder that has a circular base of radius $5$ ft and height $200$ ft $.$ Use the fact that the density of water is $\backslash (62\backslash$mathrm$\{$lb$\}/\backslash$mathrm$\{$ft$\}^\{3\}\backslash ).$

$249.[$T$]$ Find the work required to pump all the water out of the cylinder in the preceding exercise if the cylinder is only half full.