The highest pitched sound that a human ear can detect is about 21 khz. on the other hand dolphins can hear ultrasound with frequencies up to 280 khz. what is the speed of sound in water if the wavelength of ultrasound with a frequency of 2.80 x 10^5 hz is 0.510 cm?

Explain the consequences of this addiction to the brain tissue

What is special about a dc circuit ?

What is the thinnest soap film (excluding the case of zero thickness) that appears black when illuminated with light with a wavelength of 480 ? the index of refraction of the film is 1.34, and there is air on both sides of the film. express your answer in nanometers. hint 1. how to approach th