Mechanical vs. Electromagnetic Waves

Electromagnetic Waves Mechanical Waves Transverse Waves Longitudinal Waves Surface Waves Electromagnetic Waves

Mechanical Waves Waves that require a material medium Examples include water, sound, and waves along a spring or rope These materials carry the energy of the wave

Electromagnetic Waves Waves that DO NOT require a medium for motion Examples include light waves, radio waves, and X-rays All electromagnetic waves travel through space at the speed of light Since these waves can’t be observed easily, we study mechanical waves

Electromagnetic Waves

2 types of Mechanical Waves

Transverse Waves Particles of medium vibrate perpendicular to the direction of the motion of the wave Examples include guitar strings, waves in piano strings

Longitudinal Wave Particles of medium to move parallel to the direction of the wave Examples include sound waves, waves through fluids, liquids, gases or plasma

Crest – the highest point of a wave.

Trough – the lowest point of a wave.

Wavelength – a measure from one point on one wave to the corresponding point on the next wave. Measured in meters.

Wave Speed The distance a wave travels in a specific amount of time. Meters per second

Practice Problem

Equilibrium – rest position

Amplitude – the distance a wave rises or falls from the equilibrium Amplitude – the distance a wave rises or falls from the equilibrium. (How big the wave is) You need more energy to make the amplitude larger

Frequency – measurement of how many wave cycles can happen in a certain amount of time. Frequency is measured in hertz. Example: If a motor makes 50 revolutions in one second, we say it has a frequency of 50 hertz (Hz) per second.