Question

The speed of a wave in a medium is 760m/s. If 3600 waves are passing through a point in the medium in 2 min, then its wavelength is?

(a) 13.8m

(b) 41.5m

(c) 25.3m

(d) 57.2m

The question was posed to me by my college professor while I was bunking the class.

Question is taken from Sounds and Waves in portion Waves of Engineering Physics I

Answer 1

Right option is (c) 25.3m

To elaborate: Number of waves crossing a point per second,

γ=3600/(2×60)=30

ʎ=v/γ=760/30=25.3m.