Vocabulary number 5

Universe :everything that exists.

Telescope:a divice that collects light and makes distance object appear closer an larger .

refraction: the bendind of waves as they go from one substace 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 wave that pass through a point in a second.

electromagnetic spectrum:waves  of light in order by waveleght. 

                                Vocabulary number 4

Inclined plane: a nstraight, slanted surface that is not move when it is used.

screw: an inclaned plane wrapped around a central bar.

wedge: one ore  a combination of two 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 compare whith the work put into the machine.