The Young's modulus for steel is 2x1011 and its rigidity modulus is 8x1010 Nm-2. Find the Poisson's ratio and its bulk modulus.

2 answers

For homogeneous isotropic materials, simple relations exist between elastic constants (Young's modulus E, shear modulus G, bulk modulus K, and Poisson's ratio í) that allow calculating them all as long as two of them are known:

See http://en.wikipedia.org/wiki/Young's_modulus for the formulas you need
The Young's modulus for a material is 11.0 x 1010 N/m2. The material is stretched to a strain of 3.0 x 10-3. How much elastic energy will be expended?

answer is 495000.0