page 198-201 Flashcards
arrangement of all forms of electromagnetic radiation in order of frequency and wavelength
electromagnetic spectrum
low-frequency waves widely used for communication
radio waves
used for some ship and airplane communication and is used by a few radio stations
longwave radio
the highest frequency of radio waves are used by _______
cellphones
waves of higher frequency and shorter wavelength than radio waves
microwaves
uses intense beams of microwaves to cook food; the food quickly absorbs the energy of the microwave radiation and quickly becomes very hot as the radiant energy transforms into thermal energy within the food
microwave oven
uses reflected radio waves or microwaves to measure the distance and direction of faraway objects by emitting a brief pulse of microwaves and measuring the time between the initial pulse and the “echoes” produced by wave reflection
radar (radar system)
can determine an object’s speed by measuring the Doppler-effect frequency shift of a radar beam reflected from a moving object
Doppler radar
use microwaves to
transmit signals from television stations, radio stations, and cellphones around the world
communications satellites
electromagnetic radiation with a frequency slightly higher than that of visible light
ultraviolet radiation
discovered a strange form of radiation that resembled ultraviolet rays in its effect on matter but seemed to pass unhindered through wood, paper, and even human flesh. Only metal stopped this radiation (x-rays)
Wilhelm Roentgen
the most powerful form of radiation
gamma rays
consist of extremely high-frequency electromagnetic waves that are produced by reactions in the nucleus of an atom
gamma rays
showed that the energy of any electromagnetic wave is directly related to its frequency
Max Planck
the energy of a photon depends on _______
its frequency
