लकड़ी के एक बेलनाकार लट्ठे (log), जिसका व्यास 400 mm है, से काटे जा सकने वाले सबसे मजबूत आयताकार बीम की गहराई ज्ञात कीजिए।

The strain energy stored in a body of volume V, when the load is gradually applied, is (σ : stress and E : Modulus of elasticity):

The slope at the support end of a simply supported beam of length 'l' subjected to a uniformly distributed load 'w' throughout its length is equal to (where flexural rigidity EI is constant):