What are the supporting torques in terms of $d$ and $t$ at $A$ and $B$ (see Fig, P.14.57)? Determine the length of a drilied hole at a function of diameter to have the torques at $A$ and $B$ equal. Do this for $t<1.5 \mathrm{~m}$. Determine $l$ for $d=60$ min from your equation for this case.
Figure P. 14.57.