Fig. 5.1 displays a semicircular transparent plastic block. Fig. 5.2 gives a full-size drawing of a lens together with an object O. The point labelled F marks the location of a principal focus of the lens. Fig. 5.3 presents a simplified eye diagram showing rays from a distant object and the route taken by the rays inside the eye of a person with short sight. The diagram labels "lens" and "retina". Fig. 5.4 shows an uncorrected eye.
(a(i))[2]
Calculate the critical angle for the plastic.
(a(ii))[2]
On Fig. 5.1, sketch the ray’s route in the block and after it leaves the block.
(b(i))[1]
Determine the focal length of the lens.
(b(ii))[3]
On Fig. 5.2, draw two rays from the object to find the image. Label the image I.
(c)[2]
On Fig. 5.4, add another lens outside the eye to correct short-sightedness and show how the rays travel inside the eye.