Question

Explain the terms stress, strain and Hooke’s Law

Answer 1

Answer:

Hooke’s Law

Hooke’s Law states that for small deformities, the stress and strain are proportional to each other. Thus,

Stress ∝ Strain

Or, Stress = k × Strain … where k is the constant of proportionality and is the Modulus of Elasticity. It is important to note that Hooke’s Law is valid for most materials.

Stress-Strain Curve

To determine the relation between the stress and strain for a given material, let’s conduct an experiment. Take a test cylinder or wire and stretch it by an applied force. Record the fraction change in length (strain) and the applied force needed to cause the strain. Increase the applied force gradually, in steps, and record the readings.

Now, plot a graph between the stress (which is equal in magnitude to the applied force per unit area) and the strain produced. The graph for a typical metal looks as follows:

Hooke's Law

The stress-strain curves can vary with the material in question. With the help of such curves, we can understand how the material deforms with increasing loads