Sound waves travel at 350 m/s through warm air and at 3500 m/s through brass. The wavelength of a 700 Hz acoustic wave as it enters brass from warm air

Options

A. increases by a factor of 20
B. increases by a factor 10
C. decreases by a factor 20
D. decreases by a factor 10

Answer

B

Explanation

Since the frequency remains the same , we have `(lambda_("brass"))/(lambda_("air")) = (V_("brass"))/(V_("air")) implies lambda_("brass") = (3500)/(350) lambda_("air") = 10 lambda_("air")`