A dog whistle is designed to produce a sound with a frequency beyond that which can be heard by humans (between 20,000 Hz and 27,000 Hz). If a particular whistle produces a sound with a frequency of 25,000 Hz, what is the sound’s speed? Assume the wavelength of this sound wave in air is 0.013m. *
4 points
325 m/s
250 m/s
113 m/s
467 m/s

When a vertical beam of light passes through a transparent medium, the rate at which its intensity i decreases is proportional to i(t), where t represents the thickness of the medium (in feet). in clear seawater, the intensity 3 feet below the surface is 25% of the initial intensity i0 of the incident beam. what is the intensity of the beam "10" feet below the surface? (give your answer in terms of i0. round any constants or coefficients to five decimal places.)