Presentation on theme: "Radiant Energy or Electromagnetic Energy (EM)"— Presentation transcript:
1 Radiant Energy or Electromagnetic Energy (EM) All radiant energy travels at 3.0 x 108 m/sec in spaceVelocity of a wave = wavelength x frequencyVisible light is just one type of EM Energy
2 Electromagnetic Spectrum All of the forms of radiation given off by vibrating electric chargesRadiation comes in the formof vibrating or “throbbingbundles of energy” calledphotonsThe frequency of the vibratingelectric charges determineswhich type and how muchenergy will be given off
3 The entire E.M. Spectrum in order from lowest to highest frequency Radio waves: AM and FMMicrowaves: cookingInfrared: heatVisible: (ROYGBV)Ultraviolet: tanningXrays: medicalGamma:deadly radioactivity
4 Waves - Energy carried by rhythmic disturbances Two types:1. E.M. radiation move through empty space2. Mechanical require a medium (air, water or any type of matter) for movement
6 All waves have similar properties Frequency- the number of vibrations per second or the speed of the movement of the vibrating particlesAmplitude – the size of the movement of the vibrating particlesBoth are controlled by the disturbance that created the waves
7 Velocity of all waves - v=f λ f-frequency and λ is wavelength (distance between identical points on two consecutive waves)Reflection- bounce off barriers in regular waysRefraction- waves can change direction when speed changes
8 J 3300 Hz Use the formula chart!!! Velocity = f λ OR And the answer is?J 3300 Hz38 At 0°C sound travels through air at a speed of 330 m/s. If a sound wave is produced with a wavelength of 0.10 m, what is the wave’s frequency?F HzG 33 HzH 330 HzJ 3300 HzUse the formula chart!!!Velocity = f λ OR330 m/s = f x m
9 Transverse WavesIn Transverse Waves particles vibrate at right angles to the direction the wave travels.Ex. E. M. Waves, waves on a slinky or rope coil, ocean waves
10 Longitudinal or Compress ional Waves Vibrating particles move back and forth along the direction of the wave velocityParts consist of compressions and rarefactionsEx. Sound Waves
11 Sound Waves are Compression Waves Sound is produced when a compression is made.It requires a producer and a medium to travel through.The more elastic the object, the faster sound travels.
12 Sound acts like other waves Echoes are reflected sound wavesSonar uses echoes to judge distance to obstructionsHuman hearing is 20-20,000 Hz, below 10 Hz is infrasonic, and above 20,000 Hz is ultrasonic.
13 Sound Waves move through matter not through empty space. 32 One tuning fork is struck and placed next to an identical fork. The two forks do not touch. The second tuning fork starts to vibrate because of —F interferenceG the Doppler effectH resonanceJ standing wavesResonance is the vibration of another object struck by a wave of the correct frequency. Since the forks are identical, the second one receives the correct frequency to begin vibrating.