Week 3 Rainbows and Atmosphere

Question 1

what is refraction

Answer 1

change in direction of wave due to a change in its speed when passing through a medium

Question 2

what does a change over time in the electrical field induce

Answer 2

a proportional vorticity in the magnetic field

Question 3

what does a change over time in the magnetic field induce

Answer 3

proportional vorticity in the electrical field but in the opposite direction

Question 4

what is true of all refractive index and why

Answer 4

its always greater than 1 because n = c/v and v cant be greater than c

Question 5

how does refraction change with wavelength

Answer 5

longer wavelengths are refracted less

Question 6

what does Airy theory state

Answer 6

a water droplet converts the incident planar wavefront into a curved wavefront due to the spherical shape of the raindrop. This curved wavefront turns back on itself leading to interference between wavefronts giving rise to supernumeracy bands needed for rainbows

Question 7

what is Brewster’s angle

Answer 7

angle of incidence at which light with a particular polarisation is perfectly transmitted through a transparent dielectric surface with no reflection

Question 8

what are the 5 sections of the atmosphere in ascending order

Answer 8

Troposhere
Tropopause
Stratosphere
Mesosphere
Ionosphere

Question 9

give at least two functions of the atmosphere

Answer 9

1 Protect from hazardous/deadly radiation
2 Let light through to provide energy
3 Protects from rapid cooling and heating
4 Transport energy from equator to higher latitudes
5 Transport water vapour that leads to precipitation
6 Stores nitrogen, carbon dioxide and oxygen
7 Dissipation of decomposition of natural & man made emissions
8 Protection from small meteorites

Question 10

If we assume hydrostatic equilibrium what two components make up pressure

Answer 10

1 Weight of the fluid

2 Resisting force keeping the element steady