1. Energy  an object is said to have “energy” if the object has the ability to change its environment Two ways to transfer energy  1. through the application of a force (work) 2. waves  a disturbance (oscillation) that transfers energy through matter or space (no forces involved)

2. Two types of waves  1. Electromagnetic (EM)  a wave that does not need a medium to travel through We will assume that all electromagnetic waves travel at the speed of light (3 x 10 8 m/s)* in vacuum  2.99792458 x 10 8 m/s in air  2.99704645 x 10 8 m/s in water  2.24900569 x 10 8 m/s in glass  2.05618970 x 10 8 m/s medium  a material through which a wave can travel (i.e. solid, liquid, gas)

3. Two types of waves  1. Electromagnetic (EM)  a wave that does not need a medium to travel through

4. Two types of waves  1. Electromagnetic (EM)  a wave that does not need a medium to travel through medium  a material through which a wave can travel (i.e. solid, liquid, gas) 2. Mechanical  a wave that needs a medium to travel through Examples: Sound Earthquake waves

5. Two types of mechanical waves  1. transverse wave  particles of the medium vibrate perpendicularly to the direction of wave travel (s-wave (secondary) earthquake waves)

6. Two types of mechanical waves  2. longitudinal / compression wave  particles of the medium vibrate parallel to the direction of wave motion (p-wave (primary) earthquake waves, sound, deep water waves)

7. Two types of mechanical waves  surface waves (Rayleigh)  a combination of transverse and longitudinal waves (surface water waves, earthquake)

8. With waves, energy is being moved from point A to point B, not matter.