Waves

Question 1

Speed of water waves?

Answer 1

4m/s

Question 2

Wavelengths of EM waves?

Answer 2

10-12.      Gamma
10-10.       X-Ray
10-8.        UV
10-6.         Visible 
10-5.         IR
10-3.         Microwaves 
10 3.        Radio waves

Question 3

What do all EM waves have in common?

Answer 3

Travel at the speed of light

Transverse waves

Carry energy

Question 4

Use for radio waves?

Answer 4

Communications / Satelites
Mobile phones (short distances)

Question 5

Use for microwaves?

Answer 5

Mobile phones (Long distance) 
Satellite communications (TV)

Question 6

X Ray uses?

Answer 6

Bone photos

Question 7

Gamma uses?

Answer 7

Used in medicine. Sterilise medical equipment and can kill cancer cells

Question 8

Why r microwaves suited to satellite communications?

Answer 8

They have a small enough wavelength to get Through the ionosphere (a layer of charged particles)

Question 9

How many satellite stations are needed for world coverage?

Answer 9

3

Question 10

What are the advantages of fibre optics?

Answer 10

More info can be carried 
Not get hot or decay
Can easily be bent 
Cheaper than copper
They do not pick up electrical or radio interference

Question 11

How do fibre optics carry info?

Answer 11

The information is mixed with light or IR and transmitted along a glass cable. At the receiver, the info is taken out of the light.

Question 12

Distance of 1 light year?

Answer 12

9.47x10(15)m

Question 13

Hot and cold gasses?

Answer 13

Got gassed emit certain wavelengths, the same they would absorb when cold