8th Grade Science Final Exam Flashcards

Vocabulary-style flashcards covering the 8th Grade Science Final Exam study guide topics, including Forces, Motion, Newton's Laws, and Natural Selection.

Force

A push or pull acting upon an object.

Motion

Change in position relative to a reference point.

Reference Point

An object used for comparison to see if something moves.

Relative Motion

Motion compared to a starting point.

Balanced Forces

Forces where the net force is equal to $0$ and motion stays the same.

Unbalanced Forces

Forces where the net force is greater than $0$ and motion changes.

Average Speed

Total distance divided by total time.

Instantaneous Speed

The speed of an object at one specific moment in time, such as a speedometer reading.

Velocity

The speed of an object in a specific direction; it is a vector quantity.

Acceleration

The rate at which velocity changes, calculated as $\frac{Final Speed - Initial Speed}{Time}$ with units of $m/s^2$.

Newton's 1st Law (Inertia)

The law stating that objects at rest stay at rest, and objects in motion stay in motion unless acted on by a force.

Inertia

A property of matter based on mass; it is not a force.

Newton's 2nd Law

The law stating that force equals mass times acceleration ($F = ma$).

Newton's 3rd Law

The law stating that for every action, there is an equal and opposite reaction.

Friction

A force that resists motion between surfaces.

Static Friction

Friction acting on an object that is not moving, such as pushing a parked car.

Sliding Friction

Friction occurring when surfaces slide over one another, such as pushing a box across the floor.

Rolling Friction

Friction occurring when an object rolls, such as bike tires on pavement.

Fluid Friction

Friction through liquid or gas, such as air resistance on a falling leaf.

Gravity

An attractive force between all objects with mass, which increases as mass increases and decreases as distance increases.

Mass

The amount of matter in an object, which remains constant regardless of location.

Weight

The measure of the force of gravity on an object, which changes depending on location.

Linnaeus

The scientist who created the first formal system for classifying and naming organisms based on shared traits.

Lamarck

A scientist who proposed the incorrect idea of "acquired traits," suggesting organisms change during their life and pass those changes to offspring.

Lyell

A scientist who proved the Earth is millions of years old, providing the necessary time for evolution to occur.

Anning

A fossil hunter whose discoveries proved that the world's inhabitants have changed over time.

Darwin

The scientist who proposed the Theory of Evolution by Natural Selection based on observations made at the Gal
pagos Islands.

Hypothesis

A specific, testable prediction often formatted as an "If… then…" statement.

Scientific Theory

A well-supported, broad explanation of the natural world based on a body of facts.

Fossils

The preserved remains or traces of organisms that lived in the past, providing a record of how species changed over millions of years.

Natural Selection

The process by which species change over generations to survive in their environment; involves Variation, Selection, Time, and Reproduction.

Variation

The existence of different traits within individuals of a population, caused by genes or mutations.

Artificial Selection

The process where humans choose which organisms breed to achieve specific desired traits, also known as Selective Breeding.

Genes

Segments of DNA that determine traits and are passed from parents to offspring.

Mutations

Random changes in DNA that can be helpful, harmful, or neutral.

Epigenetics

The study of how behaviors and environment cause changes that "turn genes on or off" without changing the DNA sequence.