3.4.2.2 - The Young Modulus

Question 1

Up to what point are stress and strain proportional to each other?

Answer 1

The limit of proportionality.

Question 2

If stress and strain are proportional what does that mean?

Answer 2

There is a constant - the Young modulus

Question 3

Young modulus =

Answer 3

Tensile stress / tensile strain

Question 4

What is the Young modulus?

Answer 4

A measure of the stiffness of a material.

Question 5

What do engineers use the Young modulus for?

Answer 5

To make sure the materials they are using can withstand sufficient forces.

Question 6

What experiment can you use to find the Young modulus of an object?

Answer 6

Using a long thin wire of known cross sectional area measure its extension as you add known masses. Use the values calculated to work out the stress and strain, then plot a graph of stress-strain. The gradient is Young modulus.

Question 7

What is the are underneath a stress-strain graph?

Answer 7

Gives the strain energy per unit volume.