Using six $16$mm$,6$x$19$ wire ropes, an elevator is to lift a $24516$ N load to a height of $81$ m at a speed of

$4($m$)/($s$)$ and an acceleration of $1($m$)/($s$^(2))$F$\_($r$)=750$N;F$\_($a$)=492$N;Ft$=5329$N$,\backslash$sigma $\_($t$)=55$MPa,$\backslash$sigma $\_($b$)=114$MPa,p$=0\mathrm{.}91$Mpa,F$\_($f$)=9606$N$,\backslash$delta

$=53\mathrm{.}46$mm