Answer:
180000 m/s
Explanation:
The frequency of the wave is 900 Hz.
The wavelength of the wave is 200 m.
The speed of a wave is given as the product of wavelength and frequency. That is:
v = λf
where λ = wavelength
f = frequency
The speed of the wave is therefore:
v = 200 * 900 = 180000 m/s
The speed of the wave is 180000 m/s.