A simply supported prismatic concrete beam of rectangular cross-section, having a span of $8 \mathrm{~m}$, is prestressed with an effective prestressing force of $600 \mathrm{kN}$. The eccentricity of the prestressing tendon is zero at supports and varies linearly to a value of $e$ at the mid-span. In order to balance an external concentrated load of $12 \mathrm{kN}$ applied at the mid-span, the required value of $e$ (in $\mathrm{mm}$, round off to the nearest integer) of the tendon, is
A simply supported prismatic concrete beam of rectangular cross-section, having a span of $8 \mathrm{~m}$, is prestressed with an effective prestressing force of $600 \mathrm{kN}$. The eccentricity of the prestressing tendon is zero at supports and varies linearly to a value of $e$ at the mid-span. In order to balance an external concentrated load of $12 \mathrm{kN}$ applied at the mid-span, the required value of $e$ (in $\mathrm{mm}$, round off to the nearest integer) of the tendon, is