A solid may change its dimensions in 3 different ways, resulting in 3 types of **stress** (1) **Longitudinal stress** (**Tensile and Compressive stress)** (2) **Tangential or Shearing Stress**, and (3) **Hydraulic stress**.

Let’s find out the details of these stresses, as per the **class 11** *physics* syllabus.

**Longitudinal stress** [**Tensile and Compressive stress**]

Longitudinal stress can be of 2 types: Tensile stress and Compressive stress.

When forces are applied at a *right angle to the cross-sectional area* or surfaces to either elongate or compress the object, then these forces tend to cause a change in the length of the solid body and generate Longitudinal Stress. As said this stress may be of 2 types, tensile and compressive.

**Tensile stress** tends to enhance the length and **compressive stress** tries to decrease the length.

**Longitudinal Stress Formula**

Longitudinal Stress = Force applied / area of the surface

=>Longitudinal Stress= F/A

**Tangential or Shearing Stress**

when two *equal and opposite* deforming forces are applied *parallel* to the cross-sectional area of a cylinder-like object, then there is a relative displacement between the opposite faces of the cylinder.

In this case, the restoring force per unit area due to the applied tangential force is called tangential or shearing stress.

**Shearing Stress Formula | Tangential Stress Formula**

Shearing stress = Restoring force per unit area

=>Shearing stress=F/A.

**Related Post**: **Mechanical Properties of Solids**

**Hydraulic Stress**

A solid body (say sphere) placed in a fluid under high pressure is compressed uniformly on all sides. The force applied by the fluid acts in a perpendicular direction at each point of the surface of the solid body.

This is called Hydraulic Compression and this leads to a decrease in the volume of the solid.

As a result, an internal restoring force is developed inside the solid body.

The internal restoring force per unit area of the body is called Hydraulic Stress.

**Hydraulic Stress formula**

Hydraulic stress = Internal restoring force per unit area

=>Hydraulic stress =F/A

=>Hydraulic stress=hydraulic pressure