If it takes 500 seconds for the light from the sun to reach Earth, what is the distance to the sun in meters? (The speed
of light is 300,000,000 meters/second.)

i need
looking for :
given :
equation :
solution :

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.)