A zoom lens for a camera is adjusted to change its focal length from 38 mm to 304 mm. If the same amount of light is to be admitted to the lens in both cases, what is the final f-number if the original f-number was f/2.0?
What will be an ideal response?
f/16
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In age, Galactic disk stars are typically much ________ than those of the Galactic halo
Fill in the blank(s) with correct word
The angular separation of two stars is 0.1 arcseconds and you photograph them with a telescope that has an angular resolution of 1 arcsecond. What will you see?
A) The photo will seem to show only one star rather than two. B) The two stars will appear to be touching, looking rather like a small dumbbell. C) The stars will not show up at all in your photograph. D) You will see two distinct stars in your photograph.
A proton with a kinetic energy of 0.20 keV follows a circular path in a region where the magnetic field is uniform and has a magnitude of 60 mT. What is the radius of this path?
a. 4.1 cm b. 2.9 cm c. 3.4 cm d. 5.1 cm e. 2.4 cm
If a reactor produces an average power of 1000 MW for a year, how much 235U is used up assuming 200 MeV are released per fission?
A) 0.35 kg B) 1.75 kg C) 384 kg D) 1.1 × 108 kg E) 3.3 × 108 kg