The figure below shows a highly simplified schematic for heat transfer modeling during laser surgery. A laser beam of 250m is incident on the surface of the retina (assumed to be flat relative to the smaller radius of the laser) and all of it is absorbed on this surface. For the sake of simplicity, assume the heat transfer to be one-dimensional. For heat induced tissue damage to occur (by a mechanism called photocoagulation), the temperature has to reach 60C. The retinal tissue has a thermal conductivity, density, and specific heat of 0.60W/mK,1000 kg/m3, and 4178J/kgK respectively. The tissue is at an initial temperature of 37C. i. Write down the governing equation, initial and the boundary conditions for this problem. ii. Justify your selection of the governing equation. iii. In order to reach the damaged temperature at a depth of 10m into the tissue in 20 milliseconds, what laser power (in KW/m2 ) should be used? iv. During the usage of the laser, what will the surface temperature be in 20 milliseconds? v. Qualitatively sketch how the surface temperature changes with time. vi. Sketch the temperature versus tissue depth at 20 milliseconds