Why do elliptical galaxies appear yellow or red in color?
A) They contain many nebulae that glow red in color.
B) Their population is dominated by old, low-mass stars and old, red giant stars.
C) They are moving away from us so their light is highly redshifted.
D) They contain vast amounts of dust that absorbs blue light.
B) Their population is dominated by old, low-mass stars and old, red giant stars.
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A rifle is aimed horizontally at the center of a large target 60 m away. The initial speed of the bullet is 240 m/s. What is the distance from the center of the target to the point where the bullet strikes the target?
A. 48 cm B. 17 cm C. 31 cm D. 69 cm E. 52 cm
What is the orientation of the image on the retina of an eye?
A. Upright B. Inverted C. It depends on how close the object is. D. There is no way to know.
A single-slit diffraction pattern is formed on a distant screen. Assuming the angles involved are small, by what factor will the width of the central bright spot on the screen change if the wavelength of the illuminating light is doubled?
A) It will be cut to one-quarter its original size. B) It will be cut in half. C) It will double. D) It will become four times as large. E) It will become eight times as large.
What does the Grashof number mean?
What will be an ideal response?