Lecture 39 The Nature of Waves Ozgur Unal NIS – PHYSICAL SCIENCE Lecture 39 The Nature of Waves Ozgur Unal

The Nature of Waves What is wave? What is in a wave? How can you describe a wave? A wave is a repeating disturbance or movement that transfers energy through matter or space. Example: Water waves, sound wave, light etc.

The Nature of Waves Waves transfer energy Waves travel through matter or space Anything that vibrates can create wave

Mechanical Waves Some waves, such as sound and earthquake waves, require a medium to travel through. A medium can be solid, liquid or gas, or a combination of these. Not all waves require medium, such as light. Waves that require a medium to travel through are called mechanical waves. Example: Sound wave, wave in a rope or water etc. There are two types of mechanical waves: Transverse waves Compressional waves

Mechanical Waves In a transverse wave, matter in the medium moves back and forth at right angles to the direction that the wave travels. Example: Waves in a rope In a compressional wave, matter in the medium moves back and forth along the same direction that the wave travels. Example: Sound waves http://paws.kettering.edu/~drussell/Demos/waves/wavemotion.html

Water Waves Water waves are not purely transverse waves

Seismic Waves Seismic waves are a combination of compressional and transverse waves.