Why do astronomers conclude that quasars are very far away?
What will be an ideal response?
The spectra of quasars have very high redshifts. A high redshift implies a large distance according to Hubble's law.
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A neutron star is
A) the remains of a star that died in a massive star supernova (if no black hole was created). B) the remains of a star that died by expelling its outer layers in a planetary nebula. C) a star made mostly of elements with high atomic mass numbers, so that they have lots of neutrons. D) an object that will ultimately become a black hole.
When does a charging capacitor stop charging?
a) when the amount of charge on the two plates is equal b) when the potential difference across the plates of the capacitor is equal to zero volts c) when the amount of charge on the two plates is infinitely large d) when the potential difference across the plates of the capacitor is equal to the emf of the battery e) when all of the charge available in the circuit has been forced to collect on the plates of the capacitor
A material through which heat conducts slowly is called a __________
Fill in the blank(s) with correct word
A very long straight wire carries a 12-A current eastward and a second very long straight wire carries a 14-A current westward. The wires are parallel to each other and are 42 cm apart. Calculate the force on a 6.4 m length of one of the wires
(?0 = 4? × 10-7 T ? m/A) A) 5.1 × 10-4 N B) 2.2 × 10-4 N C) 5.1 × 10-6 N D) 8.0 × 10-5 N E) 8.0 × 10-7 N