(a)[2]
State what happens to the speed of light when it enters the plastic block. Explain your answer.
(b(i))[2]
On Fig. 7.2, carry on the paths of these two rays for another distance of at least $5\,\text{cm}$.
(b(ii))[2]
Using your answer to (b)(i), locate the image I of object O on Fig. 7.2 and add the label for this image.
(b(iii))[1]
Determine the height of the image I.
(b(iv))[1]
State and explain whether I is a real image or a virtual image produced by the lens.