What is the best way to determine a galaxy's redshift?
A) Find the galaxy's apparent distance, and look up the redshift based on Hubble's Law.
B) Find the color of the galaxy, and estimate its distance based on how red the galaxy is.
C) Take a spectrum of the galaxy, and measure the difference in wavelength of spectral lines from the wavelengths of those same lines as measured in the laboratory.
D) Measure the magnitude of the galaxy, estimate its distance, and calculate its redshift using Hubble's Law.
C) Take a spectrum of the galaxy, and measure the difference in wavelength of spectral lines from the wavelengths of those same lines as measured in the laboratory.
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Apparent retrograde motion occurs when a planet appears to
A) be stationary with respect to background stars B) move eastward with respect to background stars C) move due north with respect to background stars D) move westward with respect to background stars
A projectile is projected from the origin with a velocity of 30.0 m/s at an angle of 45.0 degrees above the horizontal. What is the velocity and time when the projectile hits the ground?
A. Vx = 21.2 m/s, Vy = -21.2 m/s at t = 4.33 s B. Vx = 16.7 m/s, Vy = -16.7 m/s at t = 3.33 s C. Vx = 21.1 m/s, Vy = -16.7 m/s at t = 2.83 s D. Vx = 16.7 m/s, Vy = -21.2 m/s at t = 4.33 s E. Vx = 21.2 m/s, Vy = -15.0 m/s at t = 3.33 s
Consider the following circuits. The batteries and capacitors are identical, and the switches have been closed for a very long time
Which statement is a common misconception with regard to Earth's atmosphere? a. The carbon dioxide added to the atmosphere since the year 1800 is mostly or entirely due to human burning of fossil fuels. b. All of Earth will warm at the same rate if there is global warming
c. The ozone layer in the upper atmosphere protects the lower atmosphere and Earth's surface from harmful solar UV radiation. d. Global warming and ozone depletion are two very different activities in Earth's atmosphere. e. Earth has experienced a greenhouse effect its entire planetary history.