Problem $3$

A prestressed concrete beam has a specified compressive

strength of concrete of $6000lb\frac{f}{i}{n}^2$ and the following

properties.

compressive strength of concrete

at time of initial prestress $,4000lb\frac{f}{i}{n}^2$

specified yield strength of

nonprestressed reinforcement

$60,000lb\frac{f}{i}{n}^2$

initial prestress force

$150$ kips

The extreme fiber stress in tension in the concrete im$-$

mediately after prestress transfer is limited to $?$