The distance between two successive crests of a certain transverse wave is 1.13 m. 20 crests pass a given point along the direction of travel every 18.6 s.
Calculate the wave speed. Answer in units of m/s.
So far I have gotten 1.22 for my answer by 20/18.6 x 1.13. I also tried 24.3 and that didn't work so I don't know what to do.
do they start timing at a crest?
there are 19 wavelengths between 20 crests
wave speed=distance/time=1.13/(18.6/20)
or
= 20*1.13/18.6 m/s
That gives me the wrong answer according to the website
it is correct, wonder if they are counting 20 as one sig digit? Who knows.
To calculate the wave speed, you need to understand the relationship between wave speed, frequency, and wavelength.
The formula for wave speed is:
Wave Speed = Frequency x Wavelength
In this case, we are given the wavelength, which is the distance between two successive crests, 1.13 m. We are also given the frequency information, although indirectly.
The information provided states that 20 crests pass a given point every 18.6 s. To find the frequency, we can use the formula:
Frequency = Number of Crests / Time
Therefore, the frequency is calculated as:
Frequency = 20 / 18.6 s
Now, we have both the wavelength and frequency. We can substitute these values into the formula for wave speed:
Wave Speed = Frequency x Wavelength
Wave Speed = (20/18.6 s) x 1.13 m
Calculating this expression, we find the wave speed to be approximately 1.22 m/s, which is the correct answer.
Based on the information you provided, your calculation of 1.22 is accurate. Make sure you use parentheses for the numerator (20) divided by (18.6 s) to ensure the correct order of operations.