In outer space, you observe a straight stream of electrons flowing past you at 14.5 miles per second, about the same speed that Mars moves on its orbit around the sun. 
You maneuver your spacecraft to face the current so that the electrons are moving from left to right and so that you are 10 m from the stream. Now you fire your rockets and boost your speed so that you are also moving at 14.5 miles per second, exactly at the same speed and direction as the electrons. In what direction does a compass needle point now?
A. right 
B. down 
C. left 
D. up 
E. You observe no magnetic field
Answer: E
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A. 1.66 mm B. 4.72 mm C. 0.024 mm D. 4.9 × 10-5 m E. 0.59 mm
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A monochromatic (single frequency, single wavelength) light ray in air (n = 1) enters a glass prism (n = 1.5). In the glass prism
a. both the frequency and the wavelength are the same as in air b. the frequency is the same, but the wavelength is greater than in air. c. the frequency is the same, but the wavelength is smaller than in air. d. the wavelength is the same, but the frequency is greater than in air. e. the wavelength is the same, but the frequency is smaller than in air.