The power of a lens is 4.0 diopters. What is the focal length of this lens?
A) 25 cm
B) 55 cm
C) 40 cm
D) 20 cm
E) 60 cm
A
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Photon Energy: What is the wavelength of a photon having energy 2.00 eV? (c = 3.00 × 108 m/s, h = 6.626 × 10-34 J ? s, 1 eV = 1.60 × 10-19 J)
Fill in the blank(s) with the appropriate word(s).
Why can't we see dark matter?
A. Because it doesn't exist. B. It emits only infrared radiation and X-rays and not optical light. C. All of it is too far away. D. It doesn't emit radiation of any sort. E. It is blocked by dust lanes in galaxies.
Red Rover, Red Rover, let Leslie come over. In this childhood game, you try to stop and catch a person who is running directly at you. Who would you rather pick?
A. Sean, who weighs 350 N and can run 5 m/s. B. Meihong, who weighs 250 N and can run 8 m/s. C. Deidra, who weighs 300 N and can run 3 m/s.
If the temperature of the Earth cools, how does the carbon dioxide cycle respond?
A) it increases the rate of volcanic eruptions, thus increasing the rate of carbon dioxide production B) it slows the formation of carbonate minerals in the oceans, thus pulling less carbon dioxide out of the atmosphere C) it speeds up the formation of carbonate minerals in the oceans, thus pulling more carbon dioxide out of the atmosphere D) it reduces the rate of volcanic eruptions, thus reducing the rate of carbon dioxide production