Sirius is a star with spectral type A star and Rigel is a star with spectral type B star. What can we conclude?
A) Rigel has a higher surface temperature than Sirius.
B) Rigel has a higher core temperature than Sirius.
C) Sirius has a higher core temperature than Rigel.
D) Sirius has a higher surface temperature than Rigel.
A) Rigel has a higher surface temperature than Sirius.
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An annular eclipse
A. occurs when the Moon's shadow does not completely reach Earth during a solar eclipse. B. occurs when Earth's shadow does not completely reach the Moon during a lunar eclipse. C. is a lunar eclipse that happens every November. D. is a solar eclipse that happens every November.
A 75-kg man is standing in a 20-kg boat. The man steps to the right thinking he is stepping out onto the dock. However, the following will actually happen (ignore the friction of the water or air on the boat or the man):
a. The man only moves a short distance to the right while the boat moves a larger distance to the left. b. The man only moves a short distance to the left while the boat moves a larger distance to the right. c. The man actually stays still while the boat moves toward the left. d. The boat doesn't move and the man moves to the right. e. None of the above.
In the case of constant acceleration, the average velocity equals the instantaneous velocity:
a. at the beginning of the time interval. b. at the end of the time interval. c. half-way through the time interval. d. three-fourths of the way through the time interval.
Radiation: The cylindrical filament in a light bulb has a diameter of 0.050 mm, an emissivity of 1.0, and a temperature of 3000°C. How long should the filament be in order to radiate 60 W of power? (? = 5.67 × 10-8 W/m2 ? K4)
A. 11 cm B. 9.4 cm C. 8.6 cm D. 7.2 cm E. 5.9 cm