When a body is subjected to two mutually perpendicular stresses, σx and σy, then the distance of the center of Mohr's circle from the origin is:

When a bar of length l and uniform cross-section is rigidly fixed at the upper end and hangs freely, the total elongation produced in the bar due to its own weight is given by (where w = weight per unit volume and E = Modulus of Elasticity):

The hoop stress set up in a thin cylinder subjected to internal fluid pressure is: