# Question 6

Olive oil floats on water because its density is less than the density of water. However, the refractive index of olive oil is 1,47 while the refractive index of water is 1,33.

6.1 Define the term refractive index. (2)

6.2 Calculate the speed of light through olive oil. (3)

6.3 If light travels through water and hits the water-olive oil boundary at an angle of 37°, calculate the angle of refraction of the light in olive oil. (4)

6.4 What does the refractive index of oil tell us about the optical density of olive oil compared to the optical density of water? (2)

6.5 6.5.1 If the light ray exits the oil into the air, will it refract TOWARDS or AWAY from the normal? (1)

6.5.2 Give a reason for the answer to QUESTION 6.5.1. (2)

6.6 6.6.1 At which surface is total internal reflection most likely to occur? Choose from oil and air or water and oil. (1)

6.6.2 Give a reason for the answer to QUESTION 6.6.1. (2)

6.7 Which other wave characteristic, WAVELENGTH or FREQUENCY, will change together with the speed, when a wave moves from one medium to another? (1)

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