5.2 More about refraction

Question 1

why does refraction occur

Answer 1

because the speed of light waves is different in each substance

Question 2

what does the amount of refraction that takes place depend on

Answer 2

the speed of the waves in the substance

Question 3

rest of explaining it

Question 4

sin I / sin R = C/Cs therefore what is n

Answer 4

n = C/Cs

c = speed of light

cs = speed of light in a substance

Question 5

what does ns = C/Cs show that

Answer 5

the smaller the speed of light is in a substance the greater the refractive index of the substance

Question 6

what property of the wave doesn’t change when refraction occurs

Answer 6

frequency

ns = C/Cs = Lambda / Lambda s

Question 7

consider an equation for when a light ray crosses a boundary from a substance in which the speed of light is C1 to a substance in which the speed of light is C2

Answer 7

sin I / sin R = C1/C2

Question 8

what can sin i / sin r = C1/C2 be rearranged into

Answer 8

1/c1 sin I = 1/c2 sin r

multiply this by c to get

c/c1 sin I = c/c2 sin r

Question 9

what can you subsitute in for c/c1

Answer 9

n1 the refractive index of substance 1

Question 10

what can you substitute in for c/c2

Answer 10

n2 the refractive index of substance 2

Question 11

snells law

Answer 11

n1 sin theta 1 = n2 sin theta 2

where theta 1 is I and theta 2 is r

Question 12

why is the refractive index of air mostly given as 1

Answer 12

speed of light in air at atmospheric pressures is 99.97% of the speed of light in a vacuum

therefore the refractive index of air is 1.0003

Question 13

why can white light be split into the colours of the spectrum by a glass prism

Answer 13

because white light is composed of light with a continuous range of wavelengths from red (650nm) to violet (350nm)

the glass prism refracts light by diffe3ent amounts depending on its wavelength

the shorter the wavelength in air the greater the amount of refraction