In an earlier physics course you learned about waves (sound waves, waves on the strings of musical instruments, etc.). Describe the main difference between longitudinal waves and transverse waves. Based on what you have learned in the lecture part of this course, which of these two types is an electromagnetic wave? What is vibrating as an electromagnetic wave propagates?

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.)