1-11 uv-, ir- and other forms of radiation (1.4)

• Natuurkunde
• Middelbare school
• havo, vwo
• Leerjaar 2

UV, IR and other forms of radiation

(p. 47)

Bluetooth 

- On

- VPN off

Stationary

- Books

- Pen and pencil

- iPad

Report

- NO

Lessonup

- Yes

Bags in

the cuboard

Phones in the phone holder

Lesson goals:

• Explain what fluorescence is.
• State the velocity of light.
• Explain how a mobile phone and a radio send and receive    waves.
• Explain, based on the length 

       of an aerial, which kind of 
       waves are produced. 

Explain what you see, and why you see that. 

Radiate money with a UV lamp 

Fluorescence

• Ink that gives off light when it is radiated by a UV lamp. 
  
• Fluorescent substances are often added to washingpowder and toothpaste to make clothes or teeth look whiter. 
  

Velocity

• All forms of electromagnetic radiation travels with a velocity of 300 000 km/s.
  
• This is 7 times around the 

        world in 1 second. 

• Nothing is faster than this.
  

Waves

Radio waves have a wavelength of between 1 m and 1 km

Microwaves have a wavelength of between 1 mm and 1 m

Aerial

• The length of an aerial is 1/4 of the wavelength. 

• Microwaves of police walkie-talkies 

       are about 80 cm long. 
       The most appropriate 

       aerial length for this 

       aerial is therefore 20 cm. 

Which statement is not true about fluorescence?

1. Ink is the light source
2. is added to toothpaste and washing powder
3. Fluorescence is a colour
4. Has a velocity of 300 000 km/s

With a wavelength of 40 cm, what is the ideal length of the aerial?

1. 10 cm
2. 20 cm
3. 40 cm
4. 160 cm

If an aerial is 16 cm, what will be the wavelength?

1. 4 cm
2. 8 cm
3. 16 cm
4. 64 cm

Do the following questions:

 56 to 60 (p. 48)

In your writingbook

Rules: 

- time: 10 minutes

- No talking

Finished early: search on the internet how a mobile phone works

In a nutshell:

• Fluorescent ink gives of its own light when radiated by a UV lamp. 
• The velocity of light is 300 000 km/s
• Wavelength is the distance between 

       two consecutive waves. 

• The length of an aerial is 

       1/4 of the wavelength