Lesson 11 — Refraction

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

Refraction

This lesson

• Exercise refractive index
  
• Refraction – glass to air
  
• Total internal reflection
  
• Quizizz
  

Goals

• Describe what refraction is
  
• Explain why refraction causes the image of an object to get deformed using a ray diagram
  
• Explain what the refractive index is
• Apply the refractive index
• Explain total internal reflection and the critical angle

Refraction 

Link

• Incident ray
  
• Reflected ray
  
• Refracted ray
  

• Angle of incidence
  
• Angle of reflection
  
• Angle or refraction
  

refractiveindex=​speedoflightmedium​​speedoflightvacuum​​

Exercise

See the speed of light in the following materials:

• Speed of light glass: 200 000 000 m/s

• Speed of light water: 225 000 000 m/s

• Speed of light plastic: 190 000 000 m/s
  

Imagine a light ray going from vacuum into one of these materials. Order these  materials on how much they bend the light from strongest to weakest.

Why does the refractive index have no unit?

refractiveindex=​speedoflightmedium​​speedoflightvacuum​​

n=​v​​c​​

• Refractive index (n) — no unit
  
• Speed of light vacuum (c) — m/s
  
• Speed of light medium (v) — m/s
  

Refraction — glass to air

Link

Lower to higher 

refractive index

Higher to lower refractive index

Bends towards the normal line

Bends away from the normal line

Total internal reflection

Link

Link

Goals

• Describe what refraction is
  
• Explain why refraction causes the image of an object to get deformed using a ray diagram
  
• Explain what the refractive index is
• Apply the refractive index
• Explain total internal reflection and the critical angle