Light Energy

Question 1

What are waves?

Answer 1

Waves arevibrations that transfer energy from place to place
Some waves must travel through a substance
The substance is known asthe mediumand it can be solid, liquid or gas
Sound waves must travel through a medium which vibrates as the waves travel through
Other waves, like visible light, do not need to travel through a medium
Light waves can travel through a vacuum because they do not need a medium to travel through

Question 2

What are Traverse waves?

Answer 2

Light and other types of electromagnetic radiation are transverse waves
All types of electromagnetic waves travel at the same speed through a vacuum, such as through space

Question 3

What are longitudinal waves?

Answer 3

Sound waves and waves in a stretched spring are longitudinal waves
Longitudinal waves show areas of compression and rarefaction

Question 4

What are luminous light sources?

Answer 4

Objects that give off their own light are said to beluminous (e.g. the sun, candle, torch, lamp).

Question 5

What are non-luminous light sources?

Answer 5

You can see non-luminousobjects because light from luminous objects is reflected from them (e.g. the moon).

Question 6

What are bioluminescent light sources?

Answer 6

Living things that emit light without heat are referred to asbioluminescent (e.g. blinking bacteria, flaming fungus, shimmering squid).

Question 7

What are incandescent light sources?

Answer 7

Incandescent objects emit light because they are hot, like the sun (e.g. the sun, light bulbs, flames).

Question 8

What is transmitted light?

Answer 8

Transmitted; that is, the light energy can travel through the substance. For example, light is transmitted through clear glass.

Question 9

What is reflected light?

Answer 9

Reflected from the surface of the substance or reflected (scattered) by small particles inside the substance. For example, light is reflected from opaque objects like a piece of wood and scattered by particles of water in fog.

Question 10

What is absorbed light?

Answer 10

Absorbed; that is, the light energy can be transferred to particles inside the substance. For example, the tinted glass in many cars contains a substance that absorbs some of the light energy passing through it.

Question 11

What is the electromagnetic spectrum?

Answer 11

Electromagnetic Spectrum spans an enormous range of wavelengths and frequencies. This range is known as the electromagnetic spectrum. The EM spectrum is generally divided into seven regions, in order of decreasing wavelength and increasing energy and frequency.

Question 12

What are the common designations of the Light spectrum?

Answer 12

1. radio waves
2. microwaves
3. infrared (IR)
4. visible light
   5 .ultraviolet (UV)
5. X-rays
6. gamma rays