To understand the formula representing a traveling electromagnetic wave.

Light, radiant heat (infrared radiation), X rays, and radio waves are all examples of traveling electromagnetic waves. Electromagnetic waves comprise combinations of electric and magnetic fields that are mutually compatible in the sense that the changes in one generate the other.

The simplest form of a traveling electromagnetic wave is a plane wave. For a wave traveling in the x direction whose electric field is in the y direction, the electric and magnetic fields are given by

E? =E0sin(kx??t)j^,
B? =B0sin(kx??t)k^.

This wave is linearly polarized in the y direction.

1.a. In these formulas, it is useful to understand which variables are parameters that specify the nature of the wave. The variables E0 and B0are the of the electric and magnetic fields.

Choose the best answer to fill in the blank.

1. maxima
2. amplitudes
3. wavelengths
4. velocities

b. The variable ? is called the of the wave.

Choose the best answer to fill in the blank.

1. velocity

2. angular frequency

3. wavelength

c. The variable k is called the of the wave.

Choose the best answer to fill in the blank.

1. wavenumber

2. wavelength

3. velocity

4. frequency

d. What is the mathematical expression for the electric field at the point x=0,y=0,z at time t?

1. E=E0sin(??t)j^

2. E =E0sin(??t)k^

3. E =0

4. E =E0sin(kz??t)i^

5. E =E0sin(kz??t)j^

e. For a given wave, what are the physical variables to which the wave responds?

1. x only

2. t only

3. k only

4. ? only

5. x and t

6. x and k

7. ? and t

8. k and ?

Suppose you were asked to find the torque about point p due to the normal force n in terms of given quantities. which method of finding the torque would be the easiest to use?

19. explain why a magnet from your refrigerator could not be used to lift something as heavy as a car. (chapter 7 – pages 202-203) 20. can a magnet ever have a single pole? explain your answer. (chapter 7 – page 208) 21. what happens to the wavelength of a wave if the frequency is increased? (chapter 9 – pages 280-281) 22. an ocean wave has a wavelength of 10 m and a frequency of 4.0 hz. what is the velocity of the wave? show the appropriate equation from your book and show your work with units. (chapter 9 – page 282) 23. as you sit outside, the sound of a siren becomes lower in pitch. is the emergency vehicle moving away from or towards you? explain how you know. (chapter 10 – page 315-316) 24. why are two astronauts in space unable to hear one another? (chapter 10 – page 307) 25. explain in at least 3 sentences how electromagnetic waves form. (chapter 11 – page 338-339) 26. using the chart on page 345 in your textbook, what are the three types of electromagnetic wave with wavelengths shorter than those of visible light. give an example of each. (chapter 11 – pages 345-351) 27. explain why a leaf usually appears to be green, but a rose typically appears red. (chapter 12 – page 373) 28. what is the difference in light that is refracted compared to light that is reflected? think in terms of speed of light as well as what happens to light waves when they interact with a medium. (chapter 12 – pages 369-370) 29. how are concave and convex lenses different? (chapter 13 – page 408-410) 30. what type of mirror is used in rearview mirrors in cars? why is it important that these mirrors have the warning, “objects in mirror are closer than they appear.”? (chapter 13 – page 405)

Unpolarized light of intensity so passes through two sheets of polarizing material whose transmission axes make an angle of 60∘ with each other as shown in the figure. what is the intensity of the transmitted beam, st?