Shear modulus

Shear modulus is a measure of a material's ability to resist changes in shape when a force pushes against it. It can be thought of like a measure of how "stiff" a material is. It's like if you take a block of clay, you can easily mush it into different shapes. But if you take a block of wood, it will be much harder to change the shapes because it's much stiffer. Shear modulus is a number that measures how stiff a material is.