speed of light

Speed of light

• Early experiments revealed the speed of light was really fast

Longer to the left, shorter to the right

Light as a wave pocket-photons

• Shorter wavelength mean higher frequency and more energy

• Lower wavelength mean lower frequency and lower energy

• Blue light has more energy than red light

• Ultraviolet light has more energy than infrared

Wednesday February 19th: Light count. 

White light is a mixture of different colors, roygbiv

Doppler effect:

• Frequency we hear is shifted if the source is moving

• Waves bunch up ahead of the source

• Waves spread out behind the source 

Compared to how it would sound at rest, a source coming towards you will sound

1. Higher frequency

2. Normal frequency

3. Lower frequency 

Energy and temperature

• Temp is a measure of the average internal energy of a system 

• Temp is also a measure of the average speed of the particles (atoms and molecules) in the system

• The higher the temp, the faster the particles are moving

Kevin scale- scale based on the internal energy of the matter

The motion of atoms and molecules.

-here 0 K is absolute zero where all motion “stops”

Water freezes at 273.15 K

Water boils at 373.15 K