What is the primary practical difficulty that limits the use of Hubble's law for measuring distances?
A) Redshifts of galaxies are difficult to measure.
B) The recession velocities of distant galaxies are so great that they are hard to measure.
C) We do not know Hubble's constant very accurately yet.
D) Hubble's law is only useful theoretically; it is difficult to use in practice.
E) The motion of Earth relative to the Milky Way is difficult to account for.
C
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A. 318 Hz B. 637 Hz C. 796 Hz D. 955 Hz E. 1110 Hz
How can the Doppler method be used to estimate the average orbital distance of a planet's orbit?
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In which of the following application of technology in the home is radioactivity utilized?
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A flute behaves like a tube open at both ends. If its length is 70.0 cm, and the speed of sound is 340 m/s, what is its fundamental frequency in Hz?
a. 121 Hz c. 243 Hz b. 159 Hz d. 260 Hz