2.4b Youngs Modulus

If you apply a force to deform a material then remove the force and the material returns to its original shape this is

• elastic deformation

• plastic deformation

• inelastic deformation

• unplastic deformation

If you apply a force to deform a material then remove the force and the material does not return to its original shape this is

• elastic deformation

• plastic deformation

• rubber deformation

• unplastic deformation

Non destructive testing is used

• on products in use

• on products not in use

• when you don't want to damage the material

• when you need to damage the material

Destructive testing is used

• on products in use

• on products not in use

• when you don't want to damage the material

• when you need to damage the material

We need to test materials

• to find their properties eg their stiffness or ultimate tensile strength

• to see if they work

• to see how good they are

• to make sure they will work

0.2mm² is equivalent to

• 2x10^-7m²

• 2x10^-4m²

• 200x10³m²

• 200m²

What is the stress when a force of 10N acts over a circular area of diameter 3mm?

• 1.4x10⁶ Pa

• 3.3x10^-3 Pa

• 3.3 Pa

• 354x10³ Pa

A 2m wire extends by 4mm what is the strain?

• 0.5

• 2x10^-3

• 2x10^-6

• 0.005

What is the Youngs Modulus if a stress of 25MPa causes a strain of 0.003?

• 8x10⁹ Pa

• 8x10⁶ Pa

• 8x10³ Pa

• 8x10^-3 Pa