Page 55 - Science Course 3 (Book 2)
P. 55

Mo10-L2a: What are Light Waves and Electromagnetic Waves?

































                                 Increasing wavelength                     Increasing Energy



               Wavelength decreases as frequency increases.       Microwaves range
                                                                  from about 1 mm to
               Low-frequency electromagnetic waves carry low      30 cm and are used to
               amounts of energy, and high-frequency waves carry   cook food, carry cell
               high amounts of energy.                            phone signals, and
                                                                  transmit information
               Electromagnetic waves with shorter wavelengths     by satellites.
               carry more energy than those with longer wave-
               lengths.
                                                                                         An electromagnetic wave
                           High Frequency Wave                                           that has a wavelength
                                                                                         shorter than a microwave
                                                       Time                              but longer than light is
                                                                                         called an infrared wave.

                              Period




                           Low Frequency Wave                     An electromagnetic wave
                                                                  that has a slightly shorter
                                                       Time       wavelength and higher
                                                                  frequency than light is an
                                                                  ultraviolet wave.
                                  Period






                A low-frequency, low-energy                                                   Electromagnetic
                electromagnetic wave that has a                                               waves with shorter
                wavelength longer than about 30                                               wavelengths can
                cm is called a radio wave.                                                    be harmful to living
                                                                                              things.





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