2. A 8 metre long simply supported rectangular beam which carries a distributed load 45 kg/m. experiences a maximum fibre stress 160 kg/cm2. If the moment of inertia of the beam is 640 cm4, the overall depth of the beam is
7. For a beam, if fundamental equations of statics are not sufficient to determine all the reactive forces at the supports, the structure is said to be
8. The cross sections of the beams of equal length are a circle and a square whose permissible bending stress are same under same maximum bending. The ratio of their flexural weights is,