# Shear Stress Formula

The following equation is used to calculate the shear force that is acting on a system or object.

## Shear Stress Definition

Shear stress is defined as the total stress seen acting co-planar to a materials cross section. Imagine two plate that are glued together. A equal and opposite forces are acting on each sheet, which is attempting to force the sheets apart. The stress seen between that glued piece is known as the shear stress.

## How to Calculate Shear Stress?

The following step by step problem is an example of calculating the shear stress on an object.

1. First determine the total shear force acting on the object. For this example we will say after experimental measurements we find the shear force to be 25 N.
2. Next, determine the first moment of area. We will assume this to be 30 m^3.
3. Next, determine the moment of inertia of the piece of material. Formulas for this can be found online easily for common objects. We find it to be 10 m^4.
4. Next, measure the overall thickness. It’s determined to be 1m.
5. Finally, calculate the shear stress using the formula. (25*30/10*1) = 75 N/m^2