Understanding Materials and Forces

What is Hooke's Law?

• The tension in a spring or wire is proportional to its extension from its natural length, provided the extension is not too great.

• The tension in a spring or wire is inversely proportional to its extension from its natural length.

• The tension in a spring or wire is proportional to the square of its extension from its natural length.

• The tension in a spring or wire is independent of its extension from its natural length.

• N m

• Pa

• Stress is the force per unit extension.

• Stress is the force per unit cross-sectional area.

• Stress is the extension per unit length.

• Stress is the force per unit volume.

What is the unit of stress?

• N m

• None

• Strain is the force per unit cross-sectional area.

• Strain is the extension per unit length.

• Strain is the force per unit volume.

• Strain is the force per unit extension.

What is the unit of strain?

• N m

• Pa

• None

What is a crystal?

• A solid in which atoms are arranged randomly.

• A solid in which atoms are arranged in a regular array.

• A solid in which atoms are arranged in a liquid-like structure.

• A solid in which atoms are arranged in a gaseous state.

What is a crystalline solid?

• A solid consisting of a single crystal.

• A solid consisting of many crystals, usually arranged randomly.

• A solid with atoms arranged in a liquid-like structure.

• A solid with atoms arranged in a gaseous state.

What is an amorphous solid?

• A solid with atoms arranged in a regular array.

• A solid with atoms arranged quite randomly.

• A solid with atoms arranged in a liquid-like structure.

• A solid with atoms arranged in a gaseous state.