0 3 A student sits near a lake on a sunny day. Some sunlight is reflected from the surface of the lake. Sunlight is also reflected from objects submerged beneath the surface of the lake. The light reflected from the surface makes it difficult to see the submerged objects. Sunlight that reflects from the surface of the lake is horizontally polarised. Sunlight that reflects from the submerged objects is unpolarised. The student puts on a pair of Polaroid sunglasses. The amount of light he sees reflected from the surface is significantly reduced. Explain why the student can now see the submerged objects more clearly. In your answer you should: describe the nature of an unpolarised wave explain what is meant by polarisation explain the relative effect of the Polaroid sunglasses on the light reflected from the surface and the light reflected from the submerged objects. [6 marks]