Author Question: What is the parallax angle for Proxima Centauri, which is Earth's nearest star at 4.3 ly? The ... (Read 88 times)

WhattoUnderstand

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What is the parallax angle for Proxima Centauri, which is Earth's nearest star at 4.3 ly?
 
  The earth's orbit has a mean radius of 1.5  108 km, and 1 ly = 9.46  1015 m.
  A) 1.2  10-7 degrees B) 2.1  10-7 degrees
  C) 1.2  10-14 degrees D) 2.1  10-4 degrees

Question 2

A light source radiates 60.0 W of single-wavelength sinusoidal light uniformly in all directions. What is the amplitude of the electric field of this light at a distance of 0.400 m from the bulb?
 
  (0 = 8.85  10-12 C2/N  m2, 0 = 4  10-7 T  m/A, c = 3.00  108 m/s)
  A) 162 N/C B) 52.9 N/C C) 212 N/C D) 150 N/C E) 82.1 N/C


zenzy

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Answer to Question 1

D

Answer to Question 2

D



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