Johann Bernoulli is well known in the history of mechanics for his solution of the brachistochrone problem and for his first formulation of the principle of virtual works. However, his interests extend beyond to cover almost all areas of classical mechanics including rigid bodies motions, oscillations of pendula, impacts, motions of planets, and elastic beam deformation. Bernoulli is an acute observer of physical phenomena. His problems are always inspired by concrete examples, like the work of a crane, the manoeuvre of a rudder, the inflation of a sail.
