What two observations allow us to calculate the Galaxy's mass?
A) the Sun's mass and velocity in orbit of the Galactic Center
B) the Sun's age and period of the Galactic Year
C) the Sun's orbital velocity and its distance from the Galactic Center
D) the Sun's mass and its age
E) the Sun's composition and luminosity
C
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First Law of Thermodynamics: An ideal gas undergoes the process a?b?c?a shown in the pV diagram. The heat gained by the gas in process a?b is 546 J, while in process b?c the gas loses 62.0 J of heat. In process a?b the gas performs 310 J of work, while in process c?a 223 J of work is done on the gas. How much heat is gained by the gas in process c?a?
A. -397 J B. -62 J C. 223 J D. 18 J E. -236 J
A person claims to have been abducted by aliens and subjected to painful medical procedures that left scarring. However, he refuses to allow interested scientists to study his scars. This is an example of
A) hypothesis-driven science B) discovery science C) nonscience D) pseudoscience
Heating due to the greenhouse effect is caused by the fact that our atmosphere lets
A. infrared wavelengths in but prevents heat loss at visible wavelengths B. visible light through but prevents heat loss at longer (infrared) wavelengths C. visible light through but prevents heat loss at shorter (ultraviolet) wavelengths
If Earth's axis were tilted at 30°, the daylight hours in Washington, D.C., in June would
a. remain the same. b. be greater. c. be less. d. be equal to the hours of darkness.