Star A has a radius of 200 000 km and a surface temperature of 6 000 K. Star B has a radius of 400 000 km and a surface temperature of 3 000 K. The emissivity of both stars is the same. What is the ratio of the rate of energy radiated by Star A to that of Star B?
4
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The Cassini spacecraft found evidence that the E Ring is related to Enceladus through:
A) the gravitational interactions by Enceladus on the particles in the E Ring. B) the deposition of gases from Enceladus on the particles of the E Ring making them more reflective as the gas condenses on the particles. C) a continual supply of icy particles spewed via volcanism on Enceladus. D) the impact history of Enceladus—a major impact caused parts of the moon to be ejected from the surface and cross the Roche Limit to become the E Ring. E) their common origin: both the E Ring and Enceladus have a common "ancestral" comet parent.
The large, central portion of a swirling solar nebula is called a(n) ______________
Fill in the blank(s) with correct word
A coil of wire is connected to a galvanometer. When the coil is rotated in a magnetic field, the galvanometer records a current. The current results because
a. the coil acts like a transformer b. the free electrons in the conductor experience a force when they move in the magnetic field c. an electromagnetic wave is generated d. the wire is ferromagnetic e. none of the above
In a thick bed of sedimentary rocks we find an igneous dike. The order of formation is
A) together. B) igneous before sedimentary. C) sedimentary before igneous. D) unknown.