Wave

• Wave


  A disturbance in the medium which causes the particles of the medium to undergo vibratory motion about their mean position in equal intervals of time
• Categories of waves


  • Mechanical waves
  • Electromagnetic waves
• Mechanical waves


  Waves which require any medium for their propagation
• Mechanical waves


  • Water waves
  • Sound waves
  • Waves produced on the strings and springs
• Electromagnetic waves


  Waves which do not require any medium for their propagation
• Longitudinal waves


  Mechanical waves where the displacement of the medium is in the same direction as the propagation of the wave
• Transverse waves


  Mechanical waves where the displacement of the medium is perpendicular to the direction of propagation of the wave
• Producing longitudinal waves on a spring

  1. Fix one end of the slinky

  2. Hold the other end in your hand

  3. Give it a regular push and pull quickly in the direction of its length
• Do mechanical waves travel through vacuum or empty space?
• Transverse wave


  Wave in which the particle movement is perpendicular to the direction of wave propagation
• Transverse wave


  • Crests and troughs move perpendicular to the direction of the wave
  • Wave movement is perpendicular to the particle movement
• Transverse waves


  • Waves on the surface of water
  • Light waves
• Energy transfer through waves


  1. Provide muscular energy to the string

  2. Vibrating force from the hand disturbs the particles of the string and sets them in motion

  3. Particles transfer their energy to the adjacent particles in the string

  4. Energy is transferred from one place of the medium to the other in the form of wave
• Amplitude


  Distance of the stretched string from its rest position
• Shaking the string faster

  Gives more energy per second to produce wave of higher frequency, and the wave delivers more energy per second to the particles of the string as it moves forward
• Water waves also transfer energy from one place to another
• Reflection


  When waves moving in one medium fall on the surface of another medium they bounce back into the first medium such that the angle of incidence is equal to the angle of reflection
• Angle of incident wave along the normal


  Equal to the angle of the reflected wave
• The speed of a wave in water depends on the depth of water
• If a block is submerged in the ripple tank, the depth of water in the tank will be shallower over the block than elsewhere
• Water waves enter the region of shallow water

  Their wavelength decreases
• The frequency of the water waves remains the same in both parts of water