Ultrasound with a frequency of 4.077 mhz can be used to produce images of the human body. if the speed of sound in the body is the same (2.31 km/s) as in salt water, what is the wavelength in the body? answer in units of m. 01

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

On your wedding day your lover gives you a gold ring of mass 3.67 g. 48 years later its mass is 3.44 g. on the average how many atoms were abrated from the ring during each second of your marriage? the atomic mass of gold is 197 u. don't enter units

The illuminance of a surface varies inversely with the square of its distance from the light source. if the illuminance of a surface is 120 lumens per square meter when its distance from a certain light source is 6 meters, by how many meters should the distance of the surface from the source be increased to reduce its illuminance to 30 lumens per square meter?