Wavelength = wavevelocityfrequency\frac{wave velocity}{frequency}frequencywavevelocity​

λ\lambdaλ = vf\frac{v}{f}fv​

λ = refers to the wavelength, the distance between the crests in meters (m)
v = refers to the velocity of the speed of waves are moving in a direction in meter per seconds (m/s)

λ = vf\frac{v}{f}fv​

λ\lambdaλ = 340.0m/s20.0cycles/s\frac{340.0 m/s}{20.0 cycles/s}20.0cycles/s340.0m/s​

λ\lambdaλ = 17.0 m

So, the wavelength of the sound wave is 17.0 m.
f = refers to the frequency, the wave crests that go through a point in certain time cycles per second or hertz (cycles/s or Hz)

Wave velocity (v) = 1.50 m/s
The wavelength of the wave is (λ\lambdaλ) =2.0 m

Furthermore, we have to rearrange the formula for calculating the answer:

λ\lambdaλ = vf\frac{v}{f}fv​ →\rightarrow→ f = vλ\frac{v}{\lambda}λv​

f = 1.50m/s2.00m\frac{1.50 m/s}{2.00 m}2.00m1.50m/s​

f = 0.75 waves/s

So, the frequency of the wave is 0.75 waves per second.


Suppose the speed of sound is about 300.0 m/s and the frequency of the wave crest is 15.0 cycles per second. Then, find the wavelength of the sound wave that it creates?

Solution:

Firstly, note down what is given in the question

Frequency (f) = 15.0 cycles per seconds (cycles/s)
Wave velocity (v) = 300.0 meter per second (m/s)

Now put the values in the equation:

λ\lambdaλ = vf\frac{v}{f}fv​

λ\lambdaλ = 300.0m/s15.0cycles/s\frac{300.0 m/s}{15.0 cycles/s}15.0cycles/s300.0m/s​

λ\lambdaλ = 20.0 m

So, the wavelength of the sound wave is 20.0 m.