Vocab Chapters 1-14

Chapter 1 Cause and Effect- the relationship between an event that brings about a result and what happens due to the result. Controlled Experiment- when one variable is changed and all the others are controlled or stay the same throughout the experiment. Controlled Variables-variables in an experiment that is kept the same throughout the experiment. Distance- the length of space between two points English System- a system of measuring that uses, for example, distance units in inches, yards, and miles. Experiment- any situation that is set up to observe and measure something happening Experimental Technique- the exact procedure that is followed each time an experiment is repeated. Experimental Variable- a variable in an experiment that is changed by the experimenter; the experimental variable is plotted as an independent variable on the x-axis of a graph. Hypothesis- a prediction that can be tested by experimentation Investigation- one or more experiences that are all connected to answering the same basic question. Length- a unit of measurement for distance Measurement- the act or process of measuring in multiples of a specific unit Metric System- a system of measuring that uses distance units of millimeters, centimeters, meters, and kilometers. Procedure- a collection of all the techniques you use to do an experiment Research Question- a question that is solved through investigation Scientific Evidence- any observation that can be repeated with the same results Scientific Method- a process that is used to gather evidence that leads to understanding Second- a commonly used unit of time Time- a useful measurement of changes in motion or events Trial- each time an experiment is tried Variables- factors that affect the result of an experiment Velocity- describes movement from one place to another over time and in a certain direction

Chapter 2 Accelerate- to increase speed or change direction Acceleration- change in speed over time Average Speed- how fast something moves over a certain distance Conceptual Model- a written description or diagram based on ideas and observations that are used to describe how a process or object works Deceleration- occurs when change in speed, or acceleration, is in the negative direction Dependent Variable- the variable in an experiment that changes in response to choices made by the experimenter Free Fall- the acceleration of a falling object under the influence of the Earth’s gravitational force Graphical Model- a model that shows the relationship between two variables on a graph so that the relationship is easily seen and understood Gravity- the attractive force that exists between any two objects that have mass Independent Variable- the variable in an experiment that is manipulated by the experimenter and that causes changes in the dependent variable in the experiment Instantaneous Speed- the speed of an object at a specific point in its journey Physical Models- models that are made of materials and that can be touched and measured Scientific Model- a method of representing the relationship between variables

Chapter 3 Air Friction- the opposing force created by objects moving through air Equilibrium- 1. In physics, occurs when the forces on an object are balanced, 2. In chemistry, the state in which the solute in a solution is dissolving and coming out of solution at the same rate Force- a push, a pull, or any action that has the ability to change motion Friction- the force that results from relative motion between objects Gravity- the attractive force that exists between any two objects that have mass Inertia- the reluctance of a body to change its state of motion Law of Conservation of Momentum- states that as long as interacting objects are not influenced by outside forces (like friction), their momentum before the interaction will equal their momentum after the interaction Mass- a measure of the inertia of an object; the amount of matter an object has Momentum- the mass of an object multiplied by its speed or velocity Net Force- the amount of force that overcomes an opposing force to cause motion Newton- a unit of force; Abbreviation is N Newton’s first law of motion- states any object at rest will remain at rest unless acted on by an unbalanced force Newton’s second law of motion- states that the acceleration of an object is directly proportional to the force acting on it and inversely proportional to its mass Newton’s third law of motion- states that whenever one object exerts a force on another, the second object exerts an equal and opposite force on the first Pounds- the rate at which work is done Rolling Friction- resistance created when one object rolls over another one Sliding Friction- resistance created when two surfaces rub against one another Viscous Friction- resistance created by objects moving in water or other fluids Weight- a force created by gravity

Chapter 4 Engineering- the applications of science to solve technical problems Engineering Cycle- the process used by engineers to develop new technology Engineer- a person who designs technology to solve problems Force- a push, a pull, or any action that has the ability to change motion Fulcrum- a fixed point on a lever Gear- a wheel with teeth; two or more gears can be connected together to change the speed and/or direction of rotating motion Input- includes everything you do to make a machine work Input Arm- when you place a lever on a fulcrum, the input arm is the side of the lever where the input force is applied Input force- the force applied to a machine Input Gear- the gear you turn, or apply force to Lever- a stiff structure that rotates around a fixed point called the fulcrum Machine- a type of mechanical system Mechanical Advantage- the ratio of output force to input force Mechanical System- a series of interrelated, moving parts that work together to accomplish a specific task Output- what the machine does Output Arm- of the lever on a fulcrum, the output arm is the side where output force is applied Output Force- the force a machine applies to accomplish a task Output Gear- the gear attached to the output of the machine Prototype- a working model of a design that can be tested to see if it works Simple Machine- an unpowered mechanical device, such as a lever, which has an input and an output force

Chapter 5 Chemical Energy- a type of energy stored in molecules Efficiency- the ratio of a machine’s output work to input work Electrical Energy- another term for electricity Energy- a fundamental building block of the universe Energy Transformation- the conversion from one kind of energy to another kind of energy; for example, an energy transformation occurs when potential energy is converted to kinetic energy Heat- a flow of thermal energy from one object to another object due to a temperature difference Horsepower- a unit of power Joule- a unit measuring work Kinetic Energy- Energy that comes from motion Law of Conservation of Energy- Energy is never created or destroyed, only transformed from one form to the next. Nuclear Energy- the form of energy that comes from splitting the nucleus of an atom, or fusing two nuclei of an atom Potential Energy- stored energy that comes from position Power- the rate at which work is done Radiant Energy- another term for electromagnetic energy Radiation- 1. The process of emitting radiant energy; 2. A term to describe the particles and energy that are emitted from radioactive substances. Radiation- a type of heat transfer that occurs by electromagnetic waves Solar Power- radiant energy from the sun that is harnessed for use Watt- the metric, or SI, unit of power Work- the quantity of force times distance; the result of machines performing task

Chapter 6 Circuit Diagram- the diagrammatic representation of an electric circuit Closed Circuit- a circuit in which the switch is turned to the “on” position, causing there to be no breaks anywhere in the wire Coulomb- the unit for electrical charge Electric Charge- one of the fundamentals of matter; comes in positive and negative. Electric Circuits- the structures that provide paths through which electricity travels Electrical Symbols- simple symbols used in circuit diagrams Electrically Charged- an object that has an excess amount of either positive or negative charges Electrically Neutral- an object that has equal amounts of positive and negative charges Electroscope- an instrument that is used to detect charged objects Natural World- the aspects of the world not created or constructed by people Negative Charge- one of two types of electric charge Open Circuit- a circuit in which there is a break in the wire so that current cannot flow Positive Charge- one of two types of electrical charge Static Electricity- a buildup of either positive or negative charge; consists of isolated motionless charges, like those produced by friction Versorium- the earliest version of today’s electroscope

Chapter 7 Alternating Current- an electric current that reverses its direction at repeated intervals; the abbreviation for this is AC Amperes- the unit for measuring electrical current; the abbreviation is amp Battery- a device that uses chemical energy to move electrical charges Current- the quantity that refers to the rate of flow of electric charges; current is measured in amps Direct Current- electrical current flowing in one direction only; abbreviation is DC Electrical Conductivity- the ability of a material to conduct (or carry) electricity Electrical Conductor- a material that easily carries electrical current Electrical Insulator- a material that poorly conducts current Ohm- the unit of measurement for electrical resistance Resistance- the measure of an object’s ability to conduct circuits Semiconductor- material between conductor and insulator in its ability to carry current Volt- the measurement unit for voltage Voltage- the amount of potential energy that each unit of electrical charge has

Chapter 8 Horsepower- a unit of power Kilowatt- a measurement equal to 1000 watts or 1000 joules used for one hour Kilowatt-hour (kWh)- Kilowatts used in use in one hour. Ohm’s Law- describes the mathematical relationship present in most circuits Potentiometer- a variable resistor Power- the rate at which work is done Resistors- components that are used to control current in many circuits Watt- the metric, or SI, unit of power

Chapter 9 Kirchhoff’s Current Law- states the current into a branch in a circuit equals the amount of current out of the branch Kirchhoff’s Voltage Law- states that over an entire circuit, the energy taken out must equal the energy supplied by the battery Parallel Circuit- a circuit in which the current can take more than one path Series Circuit- a circuit in which the current only has one path Short Circuit- a branch in a circuit with zero or very low resistance

Chapter 10 Electromagnet- a strong, short lasting magnet that can be made by inserting iron into a wire coil that is conducting an electric current Electromagnetic Induction- the creation of electric current when a magnet is moved inside a loop of wire; generators are devices that work using electromagnetic induction Generator- a combination of mechanical and electrical systems that converts kinetic energy into electrical energy Magnetic Field- an area of magnetic force that surrounds magnetic objects Magnetic Field IntensityMagnetic Force- a force exerted on a particle or object traveling in a magnetic field Magnetic North Pole- the end of a magnetic object that points toward the geographic north pole of the Earth Magnetic South Pole- the end of a magnetic object that points away from the geographic north pole of the Earth Permanent Magnet- a magnetic object that retains its magnetic properties without external influence

Chapter 11 Amplitude- the maximum distance from the average in harmonic motion; amplitude is often a distance or an angle Cycle- a unit of motion that repeats over and over Frequency- 1. In harmonics, the number of cycles an oscillator makes per second; 2. In waves, the number of wavelengths that pass a given point in one second Harmonic Motion- motion that repeats itself Hertz- a unit of one cycle per second used to measure frequency; the abbreviation is Hz Oscillator- a system that shows harmonic motion Period- the time for one cycle Periodic Motion- cycles of motion that repeat over and over again; the same as harmonic motion Phase- refers to where an oscillator is in its cycle System- a collection of matter and processes that occur in a certain space and can be studied; systems can be open or closed

Chapter 12 Circular Waves- waves that move in concentric circles Constructive Interference- occurs when waves add up to make a larger amplitude Continuous- connected to itself Crest- the high point on a wave Destructive Interference- occurs when waves add up to make a smaller amplitude Diffraction- the process by which waves can bend around corners or pass through openings Fundamental- the name of the first harmonic Harmonics- multiples of natural frequency Hertz- a unit of one cycle per second used to measure frequency; the abbreviation is Hz Longitudinal Wave- a wave whose oscillations are in the same direction as the wave moves Natural Frequency- describes how an object vibrates; for example, a guitar string strummed repeatedly has its own natural force Plane Waves- waves that move in straight lines Reflection- the bounce of a wave off a surface Refraction- occurs when light passes from one transparent material into another and bends Resonance- an occurrence whereby the natural frequency of a system is exactly in tune with a force applied to the system ResponseStanding wave- a wave trapped in one spot Transverse Wave- a wave whose oscillation is perpendicular to the direction the wave travels Trough- the low point on a wave Wave fronts- another term used to describe the crests of a wave

Chapter 13 Acoustics- the science and technology of sound Beat- a rapid alteration between loudness and silence Cochlea- a tiny, fluid-filled bone structure in the inner ear with three tubes and a spiral Consonance- a combination of sounds that is harmonious or agreeable Decibel- the measurement of loudness in sound Dissonance- a combination of discordant or unsettling sounds Harmonics- frequencies that are multiples of fundamental notes Harmony- an oscillation in loudness that occurs when two frequencies of sound are close but not equal Musical Scale- Frequencies of sound that fit into a special pattern Pitch- Property of a sound determined by the frequency of the waves producing it Pressure- a measure of the force felt by the walls of a container Reverberation- multiple echoes of sound Rhythm- a time pattern in sound Sonogram- special kind of graph that shows how loud sound is at different frequencies Sound- a pressure wave we can feel with our ears. Supersonic- motion that is faster than sound White Noise- an equal mixture of all frequencies, like white is a mixture of all colors

Chapter 14 Chemical Reaction- the breaking of bonds to form new substances Cone Cells- photoreceptor cells in the retina of the eye that respond to color Cyan- a greenish, light-blue that is created when red is absorbed and blue and green are reflected Electromagnet Spectrum- the whole range of light Fluorescent- a type of electrical light bulb Incandescence- the process of making light with heat Magenta- a pink-purple color that is created when green is absorbed and red and blue are reflected Nanometer- a unit of measurement that is equal to one billionth of a meter Photoluminescence- occurs when light energy makes something else give off light Pixel- a dot on your computer screen whose color can change depending on the three numbers your computer assigns to it Polarizer- a partially transparent material that lets through only one polarization of light Rod Cells- photoreceptor cells in the retina of the eye that respond to differences in brightness Subtractive Primary Colors- magenta, yellow, and cyan Terahertz- a unit of measurement that is equal to 1,000,000,000 cycles per second Visible Light- the light you can see in the range between 400 and 700 nanometers Yellow- a color that is created when blue is absorbed and red and green are reflected