Rod BD is made of steel (E 5 29 3 106 psi) and is used to brace
the axially compressed member ABC. The maximum force that
can be developed in member BD is 0.02P. If the stress must not
exceed 18 ksi and the maximum change in length of BD must not
exceed 0.001 times the length of ABC, determine the smallest-diameter
rod that can be used for member BD.