please help with the following questions

3. (a) (i) An object 6.0 cm high is 30.0 cm in front a convex mirror whose radius of curvature R is 60.0cm. Find the location of the image. [Recall: R = 2f] [3] (ii) A concave min'or has a focal length of 40.0cm. How far from the mirror should one's face he so that the image is erect and twice the size of the actual face? [3] [Hint Use v = 2u] (b) (i) A beam of light strikes a pane of glass at an angle of incidence of 70. [far is 40, nd or. [2] (ii) Find the critical angle of light going from diamond (n = 2.42) to air (11 = 1.00). [2]