waves

• waves is a process of transferring energy from one point to another point without transferring matter produced by one complete oscillation or vibrations
• progressive wave occur when the wave profile propagate with time along the direction of propagation of wave.
• stationary waves occur when the wave profile does not propagate with time
• longitudinal wave occurs when the displacement parallel to the direction of propagation
• transverse wave occurs when the displacement perpendicular to the direction of propagation
• electromagnetic wave is an example of transverse wave that consists of electric field and magnetic field which are mutually perpendicular to each other and also perpendicular to the direction of propagation
• frequency is defined as number of oscillation per second
• example of longitudinal waves are sound waves and ultrasound
• sound waves can be heard by human ear because it has frequency between 20Hz-20kHz
• mechanical waves

  • requires medium
  • made up of vibrating particles
  • e.g water waves
• electromagnetic waves are transverse waves that travel through a vacuum at the speed of light

  • does not require medium tobe specific vacuum
  • made up of oscillating electric and magnetic field
  • e.g radio waves
• wavelength is distance from one peak or trough to another peak or trough
• period is time taken for one complete cycle of wave
• amplitude is maximum displacement of particle from its equilibrium position
• wave velocity = wavelength x frequency
• the longer the wavelength, the lower the frequency
• the higher the frequency, the shorter the wavelength
• lower frequency means lower energy
• sound travels faster through solids than liquids which travel faster than gases
• speed of sound in air at room temperature is approximately 340m/s
• waves can be transverse or longitudinal
• frequency is number of oscillations per second
• frequency is measured in hertz (Hz)
• velocity is measured in m/s
• wavelength is measured in metres (m)
• frequency is measured in Hertz (Hz)
• damping

  • external damping occur when oscillating system loses energy due to overcome air friction
  • internal damping occur when oscillating system loses energy due to compressions and stretching of vibrating particles
• resonance

  • system oscillates at its natural frequency
  • system oscillates with maximum amplitude
• way to overcome damping is by applying force