$2\mathrm{.}5$ through $2\mathrm{.}7.$ Select the most economical $W-$ section for the beams shown. Assume full lateral support, and neglect the weight of the beam.

$26$

$2\mathrm{.}7$

$2\mathrm{.}8$ through $2\mathrm{.}10.$ Redesign the beams in Problems$-2\mathrm{.}5-2\mathrm{.}7$ for $F_y=50$ksi.

$2\mathrm{.}11.$ Assuming that a W $1850$ wide$-$flange beam was mistakeniy installed in the situation described in Problem $2\mathrm{.}3,$ determine the load that the new beam can carry.

$2\mathrm{.}12.$ Determine the distributed load that can be carried by a W $2157$ beam over a simply supported span of $25ft$ with lateral supports every $5ft.$