7.1.A rectangular beam of width b 15 in., effective depth d = 21.5 in., and total depth h = 24 in. spans 18.5 ft between simple supports. It will carry

a dead load of 1.08 kips/ft including self-weight, plus a service live load of 4.00 kips/ft. Reinforcement consists of four evenly spaced No. 7 (No. 22)bars in one row. The clear cover on the sides is 2 in. Material strengths are fy = 80,000 psi and f= 4000 psi. (a) Compute the stress in the steel at full service load, and using the Gergely-Lutz equation, estimate the maximum crack width. (b) Confirm the suitability of the proposed design based on Eq. (7.3).