Answer :

crisforp
V = l^3 ; where V is the volum of cube and l is the length of cube ; l > 0  ;
1000 cubic ft. = l^3 ;
10^3 = l^3 ;
l = 10 ft.
[tex]The\ volue\ of\ the\ cube:V=a^3\ (a-an\ edge)\\-------------------------\\\\V=1000\ ft^3\to a^3=1000\ ft^3\to a=\sqrt[3]{1000ft^3}\to \boxed{a=10ft}\\\\because\ (10ft)^3=1000ft^3[/tex]