CHAPTER 9 HOMEWORK
Use the following to answer questions 1-2:
Although Albert Einstein is best known for his theories of relativity, his theory of the
photoelectric effect was also a major developement in 20th century physics. He received the
Nobel Prize in Physics for his work on the photoelectric effect - not the Theory of General
Relativity.
1. What is the photoelectric effect? Give an example of a device that uses the
photoelectric effect in everyday life.
2. Describe two things about the photoelectric effect that could only be explained with
Einstein's theory.
Use the following to answer questions 3-4:
Figure 9.9a shows light from an electric arc passing through a prism, projecting a rainbow of
color.
3. Referring to Chapter 7, what is the name of the physical effect in the glass of the prism
that makes the white light split into a rainbow? How does this effect make the white
light separate into a rainbow?
4. What phenomenon, shown in Figure 9.3, makes a hot electric arc produce a rainbow
spectrum? What information can be obtained from such a spectrum?
Use the following to answer questions 5-6:
Figure 9.9b and 9.9c show two special types of spectra which have bright or dark lines at various
wavelengths.
5. What is the name of the type of spectrum shown in Figure 9.9b? What is the name of
the spectrum in 9.9c?
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6. How does Niels Bohrs theory explain the spectrum in 9.9b? You may wish to refer to
Figures 9.12 and 9.13.
7. Lasers produce light that is very different from the light of a common light bulb.
Describe at least two ways that laser light is different. You may wish to refer to Figure
9.17 and the surrounding discussion.
8. Explain how a microwave oven uses electromagnetic radiation to heat food