A sound wave travels through a glass sheet with a frequency of 2000 Hz and a wavelength of 2.5 m. It then passes into water, where the speed of sound is 1500 m/s.
Which gives the period of the wave in water and the percentage decrease in its wavelength?
6.7×10−4 s6.7\times10^{-4}\ \mathrm{s}6.7×10−4 s and 70%70\%70%
6.7×10−4 s6.7\times10^{-4}\ \mathrm{s}6.7×10−4 s and 30%30\%30%
5.0×10−4 s5.0\times10^{-4}\ \mathrm{s}5.0×10−4 s and 30%30\%30%
5.0×10−4 s5.0\times10^{-4}\ \mathrm{s}5.0×10−4 s and 70%70\%70%
112 exam-style questions on Edexcel GCSE Physics 4.3 Sound, ultrasound and infrasound, covering 4.3.1 Sound waves, vibrations and the human ear, 4.3.2 Ultrasound and infrasound, 4.3.3 Uses of ultrasound and infrasound, and 4.3.4 Sound waves passing between media. Each one has a worked solution and a mark scheme showing where the marks go.