3. A satellite is in circular orbit at a height of 5.0x 10'm above the earth's surface. The radius of the earth is 6.38x10'm and the mass of earth is 5.98x102*kg. a) Find the speed of the satellite. b) Find the gravitational field strength at this altitude. (6 marks)8. Light incident at 65 in air strikes a transparent material and produces reflected light that is linearly polarized in just one direction, satisfying the condition of Brewster's angle. a) Determine the index of refraction of the material. (6 marks) b) Calculate the angle of incidence that would yield completely polarized reflected light if the transparent material were water.Index of refraction for water = 1.33