1st class lever A lever with the fulcrum in the middle and the effort force and resistance force on opposite ends. (see/saw)
1st Law of Motion Newton's law of motion which states that an object at rest will remain at rest and an object in motion will remain in motion at constant velocity uless acted upon by an unbalanced force.
2nd class lever A lever system with the reistance force in the middle and the fulcrum and effort force on opposite ends. (wheelbarrow)
2nd Law of Motion

Newton's law of motion shows how force, mass, and acceleration are related.(Force = Mass x Acceleration

3rd class lever A lever system with the effort force in the middle and the fulcrum and resistance force on opposite ends. (tweezers)
3rd Law of Motion Newton's law of motion which states that for every action there is an equal and opposite reaction.
acceleration The rate of change in velocity.
acceleration due to gravity The rate of change in velocity because of the pull of gravity. (Earth - 9.8 meters per second per second)
altitude The distance above (poitive altitude) or below (negative altitude) the surface of the Earth.
amplitude The greatest distance from rest to crest of a wave.
antinode The point on a standing wave at which constructive interference causes maximum energy displacement.
anvil A tiny bone in the middle ear that picks up vibrations from the hammer and transmits them to the stirrup.
auditory nerve Transmits electrical impulses originating in the cochlea to the brain where they are interpreted as sound.
average speed The rate at which an object moves. Average Speed = Distance / Time
balanced forces Equal forces in opposite directions.
chemical energy The energy that bonds ions or atoms together.
cochlea A part of the inner ear that contains hundres of nerve cells attached to nerve fibers that are part of the auditory nerve.
complex machine A machine constructed of two or more simple machines.
compression A space in the medium that waves are traveling through where the particles are close together.
conduction Heat transfer through a substance or from one substance to another by direct contact of melecules.
conductor A substance which permits electrons to flow freely or transfers heat more easilu than other substnaces.
cone A nerve cell in the eye that sees color.
constructive interference When waves combine in such a way that the disturbance that results is greater than either wave alone.
convection Heat transfer in fluids caused by currents formed when there are temperature and density differences in different molecules making up the fluid.
coordinates A set of numbers used that reflect time, altitude, lattitude, and longitude used to help locate a point in space.
cornea The protective outer covering of the eye that refracts light.
crest The high point of a wave.
destructive interference When waves combine in such a way that the disturbance that results is less than either wave alone.
diffraction The bending of waves around the edge of an obstacle.
distance The length between two places.
ear canal The canal in the outer ear through which the sound moves until it hits the eardrum.
eardrum A streched membrane in the ear that vibrates at the same frequency as the sound waves that enter the ear.
efficiency A comparison of work input to work output.
electromagnetic energy Energy that is associated with moving charges.
electromagnetic wave A wave that consists of electric and magnetic fields and does not require a medium to exist.
energy conversion The change of energy from one form to another.
energy The ability to do work.
farsightedness a condition in which the eyeball is too short, causing inmages to form behind the retina; can be corrected with a convex lens.
force A push or pull that transfers energy to an object, sometines causing a change in the motion of the object.
frame of reference The background or object that is used for comparison of motion or location.
frequency The number of waves that pass a certain point in a given amount of time.
friction A force that acts in the oposite direction of motion that will cause an object to sow down gradually and stop.
gram The metric unit of mass, one thousandth of a kilogram.
gravitational kinetic energy Energy of motion caused by the pull of gravity.
gravitational potential energy Stored energy caused by an objects position relative to the effect gravity could have upon it.
gravity A force of attraction that depends on the mass of two objects and the distance between them; the force responsible for accelerating an object toward Earth at a rate of 9.8 m/s/s.
hammer A small bone in the middle ear that picks up vibrations from the eardrum and transmits them to the anvil.
inclined plane A simple machine that is a flat slanted surface which multiplies force.
inertia The tendancy of objects to remain in motion or to stay at rest unless acted upon by an outside force. (Newton's First Law of Motion)
inner ear A liquid filled portion of the ear which receives vibrations from the middle ear.
iris The colored area surrounding the pupil that controls the amount of light entering the eye.
joule The metric unit used to measure the amount of work done. (1 joule = 1 newton x 1 meter)
kinetic energy The energy that a moving object has due to its motion, the energy of motion.
latitude The angular distance north or south from the equator measured in degrees.
Law of Universal Gravitation Newtons's law that states that all objects in the universe attract each other by the force of gravity. The size of the force depends on two factors: the mass of the objects and the distance between them.
Law of Conservation of Energy A law that states that energy can neither be created nor destroyed by normal means, it can only be transfered from place to place or object to object.
lens a transparent material which refracts light.
lever

A rigid bar free to move about a single point. They may be first, second, or third class depending on the arrangement of the effort force, resistance force, and the fulcrum.

longitude The distance east or west from the prime meridian measured either in degrees or time.
longitudinal wave A wave in which the motion of the medium is parallel to the direction of the wave. It is made up of alternating compressions and rarefactions.
machine A device that makes work easier by changing force and distance or by changing the direction of the force.
mass The amount of matter in an object.
mechanical advantage The number of times a machine multiplies the effort force.
mechanical energy The energy associated with the motion of an object.
mechanical wave Any wave that disturbs a medium.
medium The material through which a mechanical wave travels.
meter The basic unit of length in the metric system.
middle ear The part of the ear which receives vibrations from the eardrum and contains the hammer, anvil, and stirrup.
momentum The massof an oject times its velocity ; determines how difficult it is to stop its motion.
motion Any change in position in a certain amount of time.
nearsightedness A condition in which the eyeball is too long, causing images to form in front of the retna; corrected with a concave lens.
newton The unit of force in the metric system. (1 N = 1kg x 1 m/s/s)
node The point on a standing wave at which destructive interference results in no energy displacement.
optic nerve The nerve that carries electrical impulses from the cochlea in the inner ear to the brain.
outer ear The part of the ear that funnels sound waves into the ear.
pendulum The object at the end of a dangling string.
photon A timy bundle of light energy.
potential energy Energy of shape or position, stored energy.
power The rate at which work is done or energy is used.
prism A transparent object that is made of sides that arenot parellel that will split white light into the colors of light it is made from. (red, orange, yellow, green, blue, and violet)
pulley A rope belt of chain wrapped around a wheel. (Can change either the amount of force or the direction of force.)
pupil The opening in the center of the eye through which light enters.
radiation The transfer of energy through empty space.
rarefaction A space in the medium that waves are traveling through where the particles are spread farther apart.
reflection Bouncing back of waves upon reaching another surface.
refraction Bending of wave due to a change in speed usually because the wave is traveling through a new medium.
resonant frequency The frequency at which a standing wave occurs.
retina A light-sensitive region that lines the eye and upon which images are formed.
rod The nerve cells in the eye that are sensitive to light and dark.
screw A simple machine that is an inclined plane wrapped around a bar to form a spiral.
second The unit of time in the metric system.
simple machine A device that accoplishes work with only one movement. (lever, pulley, inclined plane, screw, wedge, wheel and axle)
sonar Sound Navigation Ranging; a technique that uses sound waves over time to measure distance.
standing wave A wave that does not appear to be moving; occurs at the natural frequency of the material.
stirrup A tiny bone in the middle ear that picks up vibrations from the anvil and transmits them to the cochlea in the inner ear.
surface wave A wave that consits of a combination of transverse and longitudinal waves and occurs at the surface between two different mediums.
thermal energy Heat energy.
transverse wave A wave in which the motion of the medium is at right angles to the direction of the wave.
trough The low poin tof a wave.
unbalanced force Unequal forces in opposite directions.
velocity A description of speed in a given direction.
vibration A movement that follows the same path over and over again.
vissible light Wavelengths of the electromagnetic spectrum which can be seen with the unaided eye.
watt The unit of power in the metric system. (1 W = 1j/s)
wave A traveling disturbance which carreys energy from one place to another.
wave height The distance from the crest to the trough of a wave.
wave length The distance between two consecutive points on a wave.
wave speed The frequency of a wave times its wavelength.
wedge Two or more inclined planes put together that move.
weight The measure of force of attraction between two objects due to the force of gravity .
wheel and axle A machine made up of two circular objects of different sizes; a force that is applied to the wheel and transfered to the axle.
work Force acting over a distance to move an object.
work input Work that goes into a machine. (Effort force exerted over a distance.)
work output Work that comes out of a machine. (Output force exerted over a distance.)