Earthquakes and Static Electricity - Vocabulary Flashcards

A set of vocabulary-style flashcards covering key concepts from the lecture notes on earthquakes, static electricity, charging methods, electroscopes, lightning, and the structure and dynamics of the Earth.

Tropical cyclone

A devastating natural disaster that forms over warm tropical oceans, with violent winds, heavy rainfall, and storms, moving toward coastal regions and causing destruction.

Amber

A hard yellow stone observed by Thales to attract light objects when rubbed, historically linked to the discovery of static electricity.

Static electricity

A build-up of electric charges on the surface of an object; charges remain on the object and do not move under normal conditions.

Electric charge (Coulomb, C)

A property of matter that causes electric forces; the SI unit is the coulomb (C).

Positive charge

Charge resulting from a deficit of electrons (more protons than electrons); represented by a plus sign (+).

Negative charge

Charge resulting from an excess of electrons (more electrons than protons); represented by a minus sign (-).

Ion

An atom that has gained or lost electrons, becoming positively or negatively charged.

Conservation of charge

Electric charges cannot be created or destroyed; they can only be transferred from one object to another.

Friction (charging by rubbing)

Charging an object by rubbing it with another object, creating equal and opposite charges on the two bodies.

Conduction (charging by contact)

Charging an uncharged object by bringing it into direct contact with a charged object, causing charge transfer.

Induction (charging by induction)

Charging an uncharged object by bringing a charged object close without touching; opposite charges are induced, and grounding can fix the charge.

Earthing

Transferring excess charges from a charged body to the Earth; Earth can receive or supply electrons without becoming charged.

Discharging

When charged bodies equalise their charges, often by contact or grounding, reducing or removing net charge.

Electroscope

A device to detect and test electric charges, typically with a glass jar, brass disc, rod, and gold leaves that diverge when charged.

Gold leaves diverge

A sign that the electroscope is charged, indicating the presence and type of charge.

Lightning

A sudden electrostatic discharge between clouds or between a cloud and the ground, producing a bright flash and thunder.

Lightning conductor

A copper rod connected to Earth that provides a safe path for lightning to enter the ground, protecting the structure.

Storm safety (lightning)

Indoor safety steps and outdoor precautions to reduce risk during lightning, such as seeking shelter and avoiding electrical conductors.

Earthquake

A sudden shaking of the Earth caused by rupture or movement of the crust, lasting briefly and capable of causing damage.

Crust

The outermost solid shell of the Earth, divided into tectonic plates.

Tectonic plate

A large section of the Earth's crust that moves slowly atop the mantle; plates interact at boundaries.

Seismic fault zone

Regions where two or more tectonic plates meet and interact, often sites of earthquakes.

Epicentre

The point on the Earth's surface directly above the focus (hypocentre) where an earthquake originates.

Hypocentre (focus)

The point inside the Earth where an earthquake originates and seismic waves begin to spread.

Seismic waves

Vibrations that travel through the Earth during an earthquake, causing ground shaking.

Plate boundary (types mentioned)

Three moving-plate interactions: plates moving toward each other (convergent/subduction), moving apart (divergent/ridge), and sliding past each other (transform).