tailieunhanh - SAT II Physics (Gary Graff) Episode 2 Part 1

Tham khảo tài liệu 'sat ii physics (gary graff) episode 2 part 1', ngoại ngữ, ngữ pháp tiếng anh phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | CHAPTER 6 MODERN PHYSICS PARTICULATE THEORY OF LIGHT Sir Isaac Newton studied the continuous spectrum early in the seventeenth century. He passed a beam of sunlight through narrow openings into a darkened room. A white spot from the light beam appeared on the wall and when Newton placed a prism into the path of the light beam the white light disappeared and was replaced by what is called a continuous spectrum. Newton noticed that the spectrum was displaced slightly to the side of the light path. He also observed that the colors of the spectrum always appeared in a continuous band in the same order. The red light always appeared closest to the original path of the light path followed by orange yellow green blue and violet which was always deflected most from the original path of the white light. Newton recognized the bending of light refraction as the same process that occurred with water waves. Since the light exhibited the same characteristics as water waves the wave nature of light was easy to visualize. Max Planck spent the years from about 1890 to 1905 reviewing the results of Heinrich Hertz s experiments regarding the radiation of hot objects. Planck noticed that the results of Hertz s experiments could not be explained in terms of wave theory but could be explained if the energy in radiation was carried in bundles or packets of light which he called quanta. Planck theorized that the energy of the light was proportionally related to the frequency which meant that the higher the frequency of the light the higher the energy of the light. Planck related his idea to the equation E hf where E is the energy f is the frequency and h is Planck s constant. It s value is X 10-4 J S. Planck s theory is useful because it relates the frequency of light to the energy carried by the light. The light quanta suggested by Planck also shows that the line spectra emitted by energized atoms are a unique set of frequencies that can best be explained by the particle theory .