Textbook Question
The spectrum of the sodium atom is detected in the light from a distant galaxy. Use the Hubble law to calculate the distance of the galaxy from the earth.
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- 0. Math Review31m
- 1. Intro to Physics Units1h 29m
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1. Intro to Physics Units
Introduction to Units
Multiple Choice
Which of the following is the SI unit of ?
A
(joule)
B
(hertz)
C
(watt)
D
(newton)
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Verified step by step guidance1
Understand that frequency (f) is defined as the number of occurrences of a repeating event per unit time.
Recall that the SI unit of frequency is derived from the reciprocal of time, since frequency measures how many cycles happen in one second.
The SI base unit for time is the second (s), so frequency has units of 1/second or s^{-1}.
Recognize that the special name for the unit s^{-1} is the hertz (Hz), which is the standard SI unit for frequency.
Therefore, among the given options, the correct SI unit for frequency is hertz (Hz).
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