A factory siren emits a steady 500 Hz tone

PHYSICS · Single correct · A Level · Physics · Waves · Waves

Problem

A factory siren emits a steady 500 Hz tone. The speed of sound varies with temperature according to

v=331\,\text{m/s}+0.60\,\text{m/s}\;T

, where

T

is measured in °C. By how much does the wavelength of the siren’s sound change between a cold night at 0 °C and a hot afternoon at 30 °C? (a) About

0.0036\,\text{m}

longer on the hot afternoon (b) About

0.06\,\text{m}

longer on the hot afternoon (c) About

0.04\,\text{m}

longer on the hot afternoon (d) About

0.04\,\text{m}

shorter on the hot afternoon