A sound source sends waves of 400 Hz. It produces waves of wavelength 2.5 m. The velocity of sound waves is:
1000 m/s
Frequency is the number of times a wave oscillates per second and wavelength is distance between two consecutive compressions or rarefactions.
Velocity of wave (v) = frequency × wavelength
So, velocity (v) = 400 × 2.5
v = 1000 m/s