Year 8 Science: Energy and Continental Drift

Vocabulary flashcards covering the Law of Conservation of Energy, energy transformations, and the history and evidence for continental drift and seafloor spreading.

Gravitational Potential Energy (GPE)

Stored energy that relates to the pull of Earth.

Potential Energy (PE)

Stored energy.

Elastic Potential Energy

Energy involved in stretching (e.g., rubber bands, bungee cords) or compressing (e.g., rubber balls, trampolines).

Chemical Potential Energy

Energy released slowly through food digestion, rapidly through combustion of wood or petrol, or electronically via batteries.

Voltage (V)

A measure of electrical potential in a circuit.

Current (I)

The flow of energy in an electrical pathway.

Resistance (R)

The bottleneck or restriction in an electrical pathway.

Fission

An event involving a heavy, unstable atomic nucleus (e.g., Uranium) that releases explosive high-velocity kinetic particles and high-energy gamma rays.

Law of Conservation of Energy

Energy can neither be created nor destroyed; the amount present at the beginning must exactly equal the amount present at the end.

Energy Transfer

The movement of energy from one place to another, such as a golf club hitting a golf ball.

Energy Transformation

The conversion of one type of energy to another form, such as chemical potential energy becoming thermal and light energy.

Conduction

The transfer of thermal energy where heat moves through solids via touch.

Convection

The transfer of thermal energy where heat moves through liquids or gases.

Radiation

The transfer of thermal energy where heat travels as waves without contact.

Energy Efficiency

How much energy is transformed into a useful output by a device, calculated using the formula \text{Efficiency (%)} = \frac{\text{useful output energy}}{\text{input energy}} \times 100.

Alfred Wegener

The scientist who proposed the 1912 theory of continental drift.

Pangaea

The single giant land mass that Earth's continents were once connected as according to Wegener's theory.

Fossil Twins

Identical prehistoric animals found on continents separated by wide oceans, used as evidence for continental drift.

Wegener's Fatal Flaw

The fact that he had no explanation for the mechanism of how continents actually moved.

Marie Tharp

A cartographer who used raw sonar data to create the first detailed three-dimensional maps of the ocean floor, revealing the Mid-Atlantic Ridge.

Harry Hess

The scientist who proposed the theory of seafloor spreading, using sonar profiles and Tharp's maps.

Seafloor Spreading

The theory that molten rock creates new seafloor, acting as a conveyor belt to move continents.

Sonar

Technique used to locate things underwater by sending sound waves and waiting for them to bounce back.

Magnetic Striping

The "Smoking Gun" evidence consisting of symmetrical magnetic stripes on the seafloor that prove new crust is added equally to both sides.

Kilojoule (kJ) Conversion

A unit of energy where $1\,kJ = 1,000\,J$ and $1\,kJ = 0.239\,kcal$.

Megajoule (MJ) Conversion

A unit of energy where $1\,MJ = 1,000\,kJ$ or $1,000,000\,J$.