waves

Question 1

how does the velocity of light in the layer of hot air near the around compare with the velocity in the cooler air higher up

Answer 1

velocity of light moves faster in the hotter layer of air as the air is less dense

Question 2

Explain how to measure the angle of rotation of polarised light when it passes through a sugar solution

Answer 2

add a polaroid filter at one end
introduce sugar soltuion between polaroid
rotate one polaroid to give a new dark view
difference in angle between two positions in angle of rotation

Question 3

what is a stationary wave

Answer 3

waves that are produced by the superposition of two waves of the same frequency and amplitude travelling in opposite directions

Question 4

how stationary waves formed

Answer 4

two waves travelling in opposite directions
superpose constuctively if in phase
superpose destructively if out of phase

Question 5

What is total internal reflection

Answer 5

The angle at which light reflects rather than refracts

Question 6

How does an echo occur

Answer 6

When sound waves reflect off a surface and travel back to the listener

Question 7

What equipment is needed for a microwave experiment

Answer 7

Polarising filter
Metal grilled
Microwave detector
Microwave transmitter

Question 8

Why did some scientists at the time time not accost the wave theory of light

Answer 8

Lack of evidence

Question 9

Explain why two rays from the same source create a bright light

Answer 9

Waves are in phase
Waves superpose constructively
Path difference is 0

Question 10

Describe how sounds travels through air

Answer 10

Sound travels as a longitudinal wave
With oscilillations of air parallel to the direction they are travelling in

Question 11

Why does light reflecting off oil cause interference patterns

Answer 11

As light enters oil, light retracts and changes direction
As light bounces and exists oil the exiting light is out of phase
Creating bright spots and full spots due to msximas and minimas
Creating interference patterns