Physical Science Part 3

an eye condition in which objects at any distance appear blurry because of the distorted shape of the cornea
aromatic hydrocarbons
hydrocarbons that contain a ring structure similar to benzene
Archimedes' principle
the equivalence of the buoyant force on an object and the weight of the fluid displaced by the object
a point of maximum displacement midway between two nodes in a standing wave
an ion with a negative charge
central heating system
a heating system that heats many rooms form one central location
an ion with a positive charge
a substance that affects the rate of a chemical reaction without being used up in the reaction
a compound composed of carbon, hydrogen, and oxygen in which the ration of hydrogen to oxygen atoms is 2 : 1
an optical instrument that records an image of an object
concave lense
a lens that is curved inward at the center and is thickest at the outside edges
a programmable device that can store and process information
an area of a longitudinal wave where the particles of the medium are close together
compound machine
a combination of two or more simple machines that operate together
a substance that is made from two or more simpler substances and can be broken down into those simpler substances
the phase change in which a gas or vapor changes directly into a solid without first changing into a liquid
the ration of a material's mass to its volume
decomposition reaction
a chemical reaction in which a compound vbeaks down into two or more simpler substances
a unit that compares the intensities of different sounds
solids whose particles are arranged in a lattice structure
electric force
the attraction or repulsion between electrically charged objects
electric field
a field in a region of space that exerts electric forces on charged particles; a field produced by electric charges or by chaging magnetic fields
electric current
a continuous flow of electric charge
electric circut
a complete path through which electric charge can flow
electric charge
a property that causes subatomic particles such as protons and electrons to attract or repel one another
energy conservation
the practice of finding ways to use less energy or to use energy more efficently
the ability to do work
endothermic reaction
a chemical reaction that absorbs energy from its surroundings
a description of a change in which a system absorbs energy from its surroundings
a substance that cannot be broken down into simpler substances
a force that opposes the motion of objects that touch as they move past each other
frequency modulation (FM)
the number of complete cycles per unit time for a periodic motion
free fall
the movement of an object toward Earth because of gravity
frame of reference
a system of objects that are not moving with respect to one another
fossil fuels
rich deposits of hydrocarbon mixtures that formed from the remains of organisms
hertz (Hz)
the unit of measure for grequency, equal to one cycle per second
heat pump
a device that uses work to transfer thermal energy from a colder area to a warmer area
heat of vaporization
the energy a substance must absorb in order to change from a liquid to a gas
heat of fusion
the energy a substance must absorb in order to change from a solid to a liquid
heat energy
any device that converts thermal energy into work
the interaction of two or more waves that combind in a region of overlap
the rate at which a wave's energy flows through a given unit of area
integrated circuit
a thin slice of silicon that contains many solid-state components; a microchip
instantanious speed
the rate at which an object is moving at a given moment in time
input force
the force exerted on a machine
the state of matter in which a material has a definite volume but not a definite shape
linear graph
a graph in which the displayed data from a straight line
an upward force due to a pressure difference between the top and bottom of a wing
a rigid bar that is free to move atound a fixed point
an object made of any thin, transparent material that has one or two curved surfaces that can reg