Force on a Cube

Question

A cube of brass has a shear force of 1100 N acting on it. This causes the cube to deform through an angle of 0.04 degrees. What is the length of one of the cube's sides?

Answer 1

As I recall, one should write force = f = l ²τ where l is edge length TBD, τ = Gε is shear stress (by Hooke's Law), G is shear modulus of brass (from a table), ε = Δ/l is shear strain, Δ = l tanδ is displacement, and δ is displacement angle. Make sure your units work out consistently.