Question

The velocity of sound waves in a metal is found to `1400 ms^(-1)`. When they travel from metal to air its velocity changes to `340 ms^(-1)`. If the wavelength of sound waves in air is 200 m, find its wavelength in the metal

Answer 1

`V_("met") = 1400 ms^(-1) lamda_("met") = ?`
`V_("air") = 340 ms^(-1) lamda_("air") = 200 cm`
`V = n lamda`
`(V_("met"))/(V_("air")) = (lamda_("met"))/(lamda_("air")) = (1400)/(340) = (lamda_("met"))/(200)`
`rArr lamda_("met") = 823.5`