1) What is the light-gathering power of an 8 inch diameter telescope compared to
a 4-inch diameter telescope?
2) Suppose you find a piece of ancient pottery and take it to the laboratory of a
physicist friend. She finds that the glaze contains radium, a radioactive element
that decays to radon and has a half-life of 1,600 years. She tells you that there
could not have been any radon in the glaze when the pottery was being fired,
but that it now contains three atoms of radon for each atom of radium. That
is, only one quarter of the radium is left. How old is the pottery?
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3) If the rest wavelength of a certain line is 600 nm, but we observe it at 594
nm, then
A) the source is approaching us at 0.01 times the speed of light.
B) the source is approaching us at 0.001 times the speed of light.
C) the source is receding from us at 0.01 times the speed of light.
D) the source is receding from us at 0.001 times the speed of light.
4) In the atomic energy level diagram, below, transition B has half the energy of
transition A. What is the wavelength of emitted light? What is its frequency?
Sample Solution
