NASA satellites stay up because
A) they are moving so fast that they are able to "fall" around Earth.
B) their rocket engines hold them above Earth's surface.
C) there is no air resistance in outer space and thus no downward force on an orbiting satellite.
D) they are away from Earth's gravity and thus do not get pulled down toward Earth.
E) centrifugal force pulls outward on them.
A
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The Hubble Space Telescope
a. has a flawed primary mirror. b. has been repaired. c. has failed. d. none of the above
Sorted spectral data and designed the stellar spectral types
A. Prism or A Diffraction Grating |
B. Annie Jump Cannon |
C. Temperature |
D. Spectroheliometer |
E. Continuous Spectrum |
F. Joseph Van Fraunhofer |
What is the Hubble constant essentially a measure of?
a. the number of galaxies in the universe b. the expansion of the universe c. the age of the Milky Way galaxy d. the amount of dark matter in an average galaxy
Which of the following best describes natural selection?
A) It is the idea that organisms with genetic traits that improve their ability to reproduce are more likely to pass those traits on to future generations. B) It is the idea that the strong survive and the weak die off. C) It is a guess made by scientists about how life develops, but it has no hard evidence to support it. D) It is the idea that organisms naturally increase in complexity and intelligence with time.