waves on the surface of a liquid are observed to have a wavelength of 12.9 mm and a speed of 30.9 cm/s. the frequency of the wave motion is:
a. 1.8 mHz
b. 24 Hz
c. 42 mHz
d. 2.4 Hz
e. 2.4 mHz
how do i know which label to use (mHz or Hz)? and which one is correct?
To determine whether to use the label "mHz" or "Hz" when measuring frequency, we need to understand the prefixes involved.
The prefix "m" stands for milli-, which represents a factor of 1/1000 or 0.001. Therefore, 1 mHz is equal to 0.001 Hz.
In the given options, we have two frequencies: 1.8 mHz and 2.4 mHz, and two others: 2.4 Hz and 24 Hz.
To find the correct frequency, we can use the formula:
Frequency (Hz) = Speed (m/s) / Wavelength (m)
First, let's convert the given wavelength from millimeters to meters:
12.9 mm = 12.9/1000 = 0.0129 m
Now we can substitute the values into the formula:
Frequency (Hz) = 0.309 m/s / 0.0129 m
Calculating this expression, we get:
Frequency (Hz) ≈ 23.95 Hz
Therefore, the correct frequency is approximately 24 Hz.
Now, let's determine if we should use the label "mHz" or "Hz." Since the frequency we calculated is in hertz, we should use the label "Hz" for the correct answer.
Hence, the correct answer would be option b. "24 Hz."