Physics Essential Standards Covered:

Phy.2.2.2  

• Analyze transmission, refraction, and reflection of waves to conclude the following:  

  • Mechanical waves require a medium while electromagnetic waves can travel in a vacuum;  

  • When waves encounter a new medium the energy may be absorbed by the molecules of the material, transmitted changing speed (refracted) or reflected from the surface.  

  • Electromagnetic waves travel at the speed of light, c, in air or a vacuum and slow down as they enter other transparent materials according to the mathematical relationships relating wave speed, v, index of refraction, n, and angle of light measured from the normal:  (Snell’s Law);  

  • The angle that light strikes a boundary determines if it is transmitted into another transparent material or reflected;  

  • The angle beyond which all light is reflected (total internal reflection) is called the critical angle and can be found from the relationship ;  

  • Light waves are reflected from a smooth surface according to the law of reflection – the angle of incidence is equal to the angle of reflection.  

• Analyze interference and the principle of superposition in waves (mechanical and electromagnetic) to distinguish between constructive and destructive interference.