A watch dial that continues to glow after a week in the dark is almost certainly

A) fluorescent.
B) phosphorescent.
C) polarized.
D) radioactive.


Answer: D

Physics & Space Science

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A wire of diameter 1.0 mm and length 3.5 m stretches 3.5 mm when 8.0 kg is hung from it

(a) What is the Young's modulus for the wire? (b) What is the effective spring constant for the stretching wire?

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A long steel beam has a length of twenty-eight meters on a cold day when the temperature is 0°C. What is the length of the beam on a hot day when T = 39°C? (?steel = 1.1 × 10^?5/C°)

a. 28.009 m b. 28.015 m c. 28.012 m d. 28.036 m e. 28.004 m

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Which statement about Population II is false?

A) The globular clusters are their most obvious groupings. B) Their orbits around the Galaxy resemble those of comets. C) They formed first as the Galaxy formed. D) At almost five billion years old, our Sun must belong to this older Population. E) They are made of almost nothing but hydrogen and helium.

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Why doesn't the Hubble Space Telescope need adaptive optics?

What will be an ideal response?

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