Washington Comprehensive Assessment of Science (WCAS) Grade 8 flashcards
Washington Comprehensive Assessment of Science (WCAS) Grade 8 · Build recall with a focused review session.
32 cards. Read the term and the definition here. The deck at the top of this page is optional.
- Speed
- The rate at which an object covers distance, calculated as distance divided by time, usually expressed in meters per second.
- Acceleration
- The rate of change of velocity over time; it occurs when an object speeds up, slows down, or changes direction.
- Newton's first law
- An object remains at rest or moving at constant velocity unless a net external force acts on it.
- Newton's second law
- The net force on an object equals its mass times its acceleration, so greater mass needs greater force for equal acceleration.
- Newton's third law
- For every action force there is an equal and opposite reaction force, and the two forces act on different objects.
- Kinetic energy
- The energy of motion, calculated as one-half mass times velocity squared; doubling speed quadruples kinetic energy.
- Potential energy
- Stored energy due to position or arrangement; gravitational potential energy equals mass times gravity times height.
- Conservation of energy
- Energy cannot be created or destroyed; it only transfers between objects or transforms among forms in a closed system.
- Density
- The mass of a substance per unit volume, found by dividing mass by volume; it helps identify substances.
- Wave properties
- Waves transfer energy without transferring matter; wavelength times frequency equals wave speed, and amplitude relates to energy.
- Series circuit
- A circuit with one path for current; current is the same through each component, and total resistance is the sum.
- Cell theory
- All living things are made of one or more cells, cells are the basic unit of life, and new cells come from existing cells.
- Photosynthesis
- The process in chloroplasts using light, water, and carbon dioxide to make glucose and release oxygen.
- Cellular respiration
- A process in cells that breaks down glucose using oxygen to release energy, producing carbon dioxide and water.
- Nucleus
- The cell organelle that stores DNA and directs the cell's activities, including growth and reproduction.
- Mitochondria
- Cell organelles that release usable energy from food through respiration; cells with high energy needs contain many.
- Chloroplast
- A plant cell organelle containing chlorophyll that captures light energy for use in photosynthesis.
- Gene
- A section of DNA that carries instructions for a trait and can be passed from parents to offspring.
- Punnett square
- A diagram that predicts possible offspring allele combinations and phenotype ratios from two parents' genotypes.
- Natural selection
- Heritable variations that help organisms survive and reproduce become more common in later generations of a population.
- Food web
- A model of feeding relationships showing how energy flows from producers to consumers and to decomposers.
- Biotic and abiotic
- Biotic factors are living parts of an ecosystem; abiotic factors are nonliving parts such as water, sunlight, and temperature.
- Earth's layers
- Earth has a rocky crust, hot flowing mantle, liquid outer core, and solid inner core, identified by composition and density.
- Plate tectonics
- The theory that Earth's lithosphere is broken into plates that move over the mantle, causing earthquakes, volcanoes, and mountains.
- Convergent boundary
- A boundary where two plates move toward each other, forming mountains or subduction zones with volcanoes and earthquakes.
- Rock cycle
- The continuous processes that change rock among igneous, sedimentary, and metamorphic types through melting, cooling, weathering, and heat.
- Water cycle
- The continuous movement of water through evaporation, condensation, precipitation, and runoff, powered mainly by the Sun.
- Seasons
- Yearly changes in sunlight angle and day length caused by Earth's tilted axis as it revolves around the Sun.
- Moon phases
- The changing visible portion of the Moon caused by its orbital position relative to Earth and the Sun.
- Gravity in solar system
- The force that keeps planets in orbit around the Sun; its strength decreases as distance between objects increases.
- Weathering and erosion
- Weathering breaks rock into pieces in place, while erosion transports those pieces and deposition lays them down.
- Earthquake waves
- Seismic waves released along faults; P waves arrive first, S waves second, and surface waves typically cause the most damage.