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
A star-forming region in the Large Magellanic Cloud.
Looking toward the Sun from Alpha Centauri in Celestia
Using Parallax to Determine Distance
Hints of Earth’s Early Appearance
Layers of Earth
Moving currents are affected by Earth’s rotation