WGU C165 EXAM QUESTIONS AND ANSWERS

The study of energy and forces of matter Physics The study of the properties of matter and how matter changes; atoms, molecules and their interactions to form substances Chemistry the study of the moon, stars, and other objects in space astronomy The scientific study of earth and the universe around it including structure, materials and processes Earth Science The experimental factor that is manipulated; the variable whose effect is being studied. independent variable The measurable effect, outcome, or response in which the research is interested. dependent variable Structures that scientists build to represent something else. Physical Model a verbal or graphical explanation for how a system works or is organized conceptual model A description of a system using mathematical concepts and language like an equation. mathematical model a computer program that models an event or object computer model Only falsifiable statements can be subject to scientific inquiry principle of falsification a statement that is worded so that it is falsifiable, or disprovable, by experimental results falsifiable statement Concise statement that summarizes the results of many observations and experiments Law A well-tested explanation for a wide range of observations or experimental results. scientific theory The theory that the universe originated in a huge explosion that released all matter and energy. Big Bang Theory Sections of the Earth's crust that move due to convection currents. tectonic plates The hypothesis that the continents slowly move across Earth's surface. continental drift International System of units based on the metric system and units derived from the metric system SI system kilogram (kg) SI unit for mass meter (m) SI unit for length seconds (s) SI unit for time Kelvin (K) SI unit for temperature prefix used in the International System to indicate a power of 10 SI prefix centi (c) SI prefix meaning 0.01 milli (m) SI prefix meaning 0.001 kilo (k) SI prefix meaning 1,000 Micro SI prefix meaning .000001 Nano (n) SI prefix meaning . Mega (M) SI prefix meaning 1,000,000 The distance an object travels per unit of time Speed Amount of space occupied by an object Volume Mass per unit volume Density Mass divided by volume D=m/v Density formula a relationship in which one variable increases with an increase in another variable or vice versa direct relationship a relationship in which one variable decreases when another variable increases and vice versa inverse relationship defined in terms of standards base quantity a physical aspect described by a combination of base quantities derived quantity The speed of an object in a particular direction Velocity Change in velocity divided by the time it takes for the change to occur Acceleration Speeds up Slows down And/or Changes direction Acceleration occurs when an object A push or pull exerted on an object Force Newton (N) SI unit for force The combination of all forces acting on an object net force forces acting on an object that combine and form a net force of zero balanced forces Forces that produce a nonzero net force, which changes an object's motion unbalanced forces (An object continues in uniform motion in a straight line/ at rest unless a resultant force acts.) The net force on an object is the cause of its acceleration Newton's First Law The tendency to keep the same motion- remaining at rest or maintaining the same velocity Inertia The acceleration of an object depends on the mass of the object and the amount of force applied. F=ma Newton's Second Law For every action there is an equal and opposite reaction Newton's Third Law The force that two surfaces exert on each other when they rub against each other Friction The force of friction between two objects that are moving against each other kinetic friction frictional force that prevents two surfaces from sliding past each other static friction A force of attraction between objects that is due to their masses. Gravity mass times velocity linear momentum Momentum is conserved when two or more objects collide. Momentum may transfer but total momentum within the group stays the same Law of conservation of momentum The ability of a material to bounce back after being disturbed Elasticity Force exerted on an object that causes it to move Work The ability to do work or cause change Energy