Warm Up 1.What kind of electromagnetic radiation has a wavelength of 3.0 m? What is its frequency? 2.What is the wavelength of light that has a frequency of 5.88x10 14 Hz ? What color is it? 3.What are the primary colors by addition? Subtraction? 4.What is the difference between color by addition and color by subtraction?

Reflection Reflection occurs when a wave strikes an object and bounces off of it Mirror Light

Reflection Reflection occurs when a wave strikes an object and bounces off of it Mirror Light

The angle of reflection must equal the angle of incidence LAW OF REFLECTION

The law of reflection says that light reflects (bounces) off of an object at the same angle at which the light hits it.

Examples of Reflection Light bounces off a mirror Bats use echolocation (sound waves bounce off of other objects)

REFLECTION EXAMPLE #2 Tinted windows on a car Tinted windows make it cooler inside cars by reflecting light away from the window. Reflection keeps heat out! What wave carries heat that we learned about from the EM spectrum?

Mirror

Two Types of Reflection Flat surfaces reflect perfectly! Rough surfaces reflect all over the place!

Refraction Refraction is the bending of a wave caused by the change in its speed as it moves from one medium to another – What are some mediums that waves travel through? – Does light need a medium to travel? Liquids, Air, Solids NO! It can travel through SPACE!

New Vocabulary Opaque- not able to be seen through Transparent- see through

When does it reflect/refract? If an object is opaque, the light will reflect because light cannot pass through a solid object. – Mirror – A book If an object is transparent, the light will refract because light can pass through the object. – Water – Prism

Refraction of Light in Water Light travels faster in air than in water – (water is more dense than the air…same goes for glass or any other medium more dense than air) Because of this difference in speed, refraction causes underwater objects to appear closer to the surface than they really are

Refraction (Slowing Down) When a wave passes into a medium that makes it slow down, the wave will bend toward the normal Air Water

Refraction (Slowing Down) When a wave passes into a medium that makes it slow down, the wave will bend toward the normal Air Water

Refraction (Speeding Up) When a wave passes into a medium that makes it speed up, the wave will away from the normal Air Water

Refraction (Speeding Up) When a wave passes into a medium that makes it speed up, the wave will away from the normal Air Water