Electromagnetic waves and investigating infrared.

Question 1

What is refraction?

Answer 1

When a wave crossed a boundary between two materials it can change direction - refraction.
(changes direction)

Question 2

Waves are only refracted when?

Answer 2

They meet a boundary at an angle.

Question 3

What type of waves is electromagnetic waves?

Answer 3

Transverse.
They transfer energy from a source to an absorber.
(e.g campfire is a source, it transfers energy to its surroundings by giving out infrared radiation, infrared radiation is a type of EM wave, absorbed by objects, transferred to thermal energy stored which cause object to heat up)

Question 4

What are all the electromagnetic waves in order?
(electromagnetic spectrum)
7

Answer 4

Radio waves
Microwave
Infra red
Visible Light
Ultra Violet
X rays
Gamma Rays

Question 5

What is the electromagnetic spectrum split up into based up of?

Answer 5

Wavelength and frequency.
Radio waves have long wavelength and low frequency, gamma rays have the shortest wavelength and highest frequency.

Question 6

What does the amount of infra red radiation an object gives out is based on?

Answer 6

The temperature and surface (how rough or shiny it is)

Question 7

What type of cube can you use to investigate how much infrared radiation different surfaces emit?

Answer 7

A Leslie tube, which is a hollow metal cube. The four faces have different surfaces, e.g matt black paint, matt white paint, shiny metal and dull metal.

Question 8

Investigating emissions with Leslie cube practical.

Answer 8

1. Place an empty leslie cube on a heatproof mat.
   2) Draw a square around the cube that is 10cm from all faces of the cube.
   3) Fill the leslie cube and wait for the cube to warm up
   4) Use the square you’ve drawn to hold an infrared detector 10cm away from one of the cubes vertical faces.
   5) Record amount of IR radiation it detects.
   6) Repeat for each face.