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Stress
Beginner
Force per unit area inside a deformed body.
σ = F/AStress is the internal force per unit area, σ = F/A, in pascals. It may be tensile, compressive or shear.
A 1000 N load on a 1 mm² wire: 1000 MPa.
Stress is not force.
In more detail
Stress is force per unit area in a solid, σ = F/A. It can be tensile, compressive or shear, depending on the direction of the force.
Real-world uses
- Engineers calculate stress in beams and cables to check safety.
- Aircraft structures are designed for maximum stress in flight.
- Civil engineers check that a bridge cable stays within its stress limit so it does not break under its load.
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Frequently asked questions
What is the difference between stress and pressure?
Stress can act in different directions inside a solid, while pressure in a fluid is the same in all directions.
What units are used?
Pascals, the same as pressure.
Is stress the same as pressure?
They have the same units and formula, but stress applies to solids and can be directional, while pressure acts equally in all directions in a fluid.
Related topics in Fluids & Elasticity
Capillary rise · Cohesion and adhesion · Elasticity · Strain · Hooke's law for solids · Young's modulus