lunes, 20 de septiembre de 2010

the outer solar system

comet: a ball of rock and ice that orbits the sun


meteorid:a small asteroid wich may be far out in the solar system



meteor : a meteorid that enters Earth´s atmosphere and burns with a streak of light



meteoride:any part of a meteorid that reaches to Earth´s surface




the inner solar system

planet: a large body orbiting a star such as the sun


solar system : a star sushs as the sun and all the objects orbitng it



asteroid: a rocky metallic object that orbits the sun











kleper´s laws: laws that summarize the movements of the planets


the moon in motion

phases of the moon:the shape of lighted part of the moon seen from earth at any time


lunar eclipse v: a blocking  of a viewof the full moon when the moon passes  into Earth´s shadow



solar eclipse : a blocking out of a solar view of the sun when Earth passes throught the moon shadow



tide: the regular rise and fall of the water level along a shortline







Earth and the Sun

rotation . a complete spin on an axis













international date line: the180° line of longitude


standard time zone:a belt 15° wide in longitude in which  all places have the same time


revolution : one complete trip aroun the sun







the tools of astronomers

universe:everything that exist














telescope:a divice that collects light and make distands object apear closser and larger


refraction. the bending of waves as they go from one substance to another


reflection:the bouncing of waves off a surface




wavelength:the distance from one peak to the next on a wave


frequency:the number of waves that pass throught a point in a second



electromagnetic spectrum:waves of light in order by wave lenght





How inclined Planes Work

Inclines Planes:a straight,slantedsurface that is not moved when it is used

screw: an inclined plane wrapped around a central bar.

 
wedge:one or a combination of inclined planes that is moved when used

compound machine:a combination of two or more machines


efficiency:a ratio of the work done by a machine compared with the work put into the machine