The drawing shows a crystalline slab (refractive index 1.750) with a rectangular cross section. A ray of light strikes the slab at an incident angle of 01 = 44.09, enters the slab, and travels to point P. This slab is surrounded by a fluid with a refractive index n. What is the maximum value of n such that total internal reflection occurs at point P? Number Units vWhen a diverging lens is held 14.5 cm above a line of print, as in Figure below, the image is 5.3 cm beneath the lens. {a} Is the image real or virtual? (b) What is the focal length ofthe lens? ld'l Diverging lens (in (a) The image is v . [blNumber n Units v Your friend has a near point of 118 cm, and she wears contact lenses that have a focal length of 30.0 cm. How close can she hold a magazine and still read it clearly? Number n Units v The distance between the lenses in a compound microscope is 18 cm. The focal length of the objective is 1.5 cm. If the microscope is to provide an angular magnication of 64 when used by a person with a normal near point (25 cm from the eye}, what must be the focal length of the eyepiece? Number n Units v