If the star Alpha Centauri, 4.3 light years distant from the Earth, were to explode this instant, we would not be aware of this event until 4.3 years from now.

a. true
b. false


a. true

Physics & Space Science

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Which feature of Neptune's atmosphere has disappeared since the Voyager 2 fly-by?

a. white methane clouds b. Great Dark Spot c. belt-zone circulation d. Great Red Spot e. its bluish hue

Physics & Space Science

A 1.00 kg stone attached to a 1.00 m long string is traveling in a vertical circular orbit. What is the minimum tangential velocity at the top of the vertical circular orbit to keep the string from going slack?

A. 5.63 m/s B. 5.31 m/s C. 5.00 m/s D. 4.50 m/s E. 3.13 m/s

Physics & Space Science

The redshift of the galaxies is correctly interpreted as

A) the differences in temperatures and star formation in old and young galaxies. B) a Doppler shift due to the random motions of galaxies in space. C) an aging of light as gravity weakens with time. D) space itself is expanding with time, so the photons are stretched while they travel through space. E) placing our Galaxy near the center of the Local Group.

Physics & Space Science

Given that the above energy profiles have the same scale, which of the reactions would require the most energy?

A) a B) b C) c D) d E) none of the above

Physics & Space Science