Mechanical Properties of Matter (Day 2)

Resistance of a material to change in shape and size.

Which of the mechanical properties has the above behaviour?

• Strength

• Stiffness

• Elasticity

• Ductility

Plastic deformation occurs when a material is deformed beyond its elastic limit.

• True

• False

The unit for "Strain" is m².

• True

• False

The straight line graph (OA) obeys Hooke’s law which states ‘Below the proportionality limit, the restoring force, 𝐹_𝑠 is INVERSELY proportional to the extension, 𝐹_𝑠=−𝑘𝑥, where 𝑥 is the amount of extension.

• True

• False

What happened at point D?

• The change in the internal structure of the material.

• The force (stress) on the material is maximum and is known as the breaking force (stress).

• This is the point where the material breaks or fractures.

Young’s modulus DOES NOT depend to the length of the wire, but it depends on the MATERIAL that made the wire.

• True

• False