The current during electrical oscillations in the oscillating circuit changes over time depending on the dependence I(t) =Imax sin(8πt / t0 +π/5), t0-constant, Imax - amplitude value of current. Find the period of oscillations. Write an expression for the time change of charge. Determine the amplitude value of the charge.

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.)