This book covers the essential elements of engineering mechanics of deformable bodies, including mechanical elements in tension-compression, torsion, and bending. It emphasizes a fundamental bottom up approach to the subject in a concise and uncluttered presentation. Of special interest are chapters dealing with potential energy as well as principle of virtual work methods for both exact and approximate solutions. The book places an emphasis on the underlying assumptions of the theories in order to encourage the reader to think more deeply about the subject matter. The book should be of special interest to undergraduate students looking for a streamlined presentation as well as those returning to the subject for a second time.