Forces, Flight, Seismology, and Earth's Interior

Vocabulary practice flashcards defining key scientific concepts in Newton's laws of motion, principles of flight, earthquake seismology, and Earth's layered interior.

Force

A push or a pull acting on an object that can change its motion, measured in Newtons (N) or pounds (lbs).

Newton's First Law of Motion

An object at rest remains at rest unless acted upon by an unbalanced force; an object in motion remains in motion at a constant velocity unless acted upon by an unbalanced force.

Newton's Second Law of Motion

The acceleration of an object depends on its mass and the force applied ($F = m \times a$).

Newton's Third Law of Motion

For every action, there is an equal and opposite reaction.

Balanced Forces

Equal and opposite forces acting on an object that result in no change in motion (the object stays at rest or maintains a constant velocity).

Unbalanced Forces

Opposing forces that are unequal, causing a change in an object's motion (causing it to start, stop, speed up, slow down, or change direction).

Lift

The upward force created when wings deflect air downward, causing an equal and opposite upward push on the aircraft.

Weight (Gravity)

The downward force acting on an aircraft pulling it toward Earth.

Thrust

The forward force that pushes an aircraft through the air.

Drag

The backward force opposing the forward movement of an aircraft through the air.

Angle of Attack

The angle between the airplane wing and oncoming air; increasing this angle redirects more air downward to create more lift.

Altitude

The height of an aircraft or object above the ground.

Earthquake

Shaking of the ground caused by the sudden movement of rocks along a fault when underground stress is released.

Stress

Pushing and pulling forces acting on underground rocks and tectonic plates.

Fault

A crack or zone of weakness in Earth's crust along which sections of rock slide or move.

Ramapo Fault

An ancient fault line located within the North American Plate extending through New York, New Jersey, and Pennsylvania.

Seismic Waves

Vibrations or energy waves generated during an earthquake that travel through Earth.

Focus

The exact location deep underground where an earthquake originates and energy is released.

Epicenter

The location on Earth's surface directly above the focus.

P-Waves (Primary Waves)

The fastest compression ("push-pull") seismic waves that arrive at a station first and can travel through solids, liquids, and gases.

S-Waves (Secondary Waves)

Slower shear ("shake") seismic waves that arrive second, move side-to-side, and can only travel through solids.

Seismograph

An instrument that detects and records seismic waves.

Seismogram

The written recording or graph produced by a seismograph, used to calculate an earthquake's distance and magnitude.

Crust

Earth's solid outermost layer, made up of thick, less dense granitic continental crust and thin, denser basaltic oceanic crust.

Lithosphere

The rigid outer layer of Earth composed of the crust and the solid, upper rigid mantle.

Asthenosphere (Plastic Mantle)

The partially melted, thick, gooey layer of the mantle directly beneath the rigid mantle upon which the lithosphere floats.

Mantle

The thick layer beneath the crust that is part solid and part melted.

Outer Core

The liquid, melted metallic layer (iron and nickel) beneath the mantle.

Inner Core

The solid metallic center of Earth made of iron and nickel.

Vibration Frequency (High/Low)

The speed of ground shaking during an earthquake, which affects whether tall or short buildings remain stable or become unstable.