Waves

• What does a wave transfer?

  Energy.
• What causes a wave?

  Vibration.
• What is a transverse wave?

  Vibration is at a right angle(up and down) compared to the direction of the wave.
• What is a longitudinal wave?

  Vibration is parallel(side to side) compared to the direction of the wave.
• What is a compression?

  It's where particles in a longitudinal wave are closest together.
• What is a rarefaction?

  It's where particles in a longitudinal wave are furthest.
• What is the amplitude of a wave?

  Distance from the middle of a wave to the top or bottom.
• What is a wavelength?

  Distance from one point of a wave to the same point on the next wave.
• What is frequency?

  The number of waves that go past a point in a second.
• What is the wave=speed equation?

  Wave-speed = frequency x wavelength

  $v =$$fλ$
• What speed do EM waves travel?

  300, 000, 000 m/s (300 million m/s)
• What speed does sound travel at?

  330 m/s
• Name the four things that may happen when light strikes a material?

  Transmission, reflection, refraction and absorption.
• What is the law of reflection?

  Angle of incidence = angle of reflection.
• What is refraction?

  When wave bends (because it enters a medium with a different density).
• List the 7 EM waves in order of longest to shortest wavelength.

  Radio, microwave, infrared, visible light, ultraviolet, X-rays, gamma rays.
• Which EM wave has the highest frequency?

  Gamma.
• Which EM wave has the highest energy?

  Gamma
• Which three EM waves are ionising?

  Gamma, X-rays and UV.
• What are radio waves used for?

  Television and radio.
• What are microwaves used for?

  Satellite communication, cooking food.
• What are infrared waves used for?

  Heating, cooking food, infrared cameras.
• What is visible light used for?

  Fibre optic communication.
• What are ultraviolet waves used for?

  Sunbed, energy efficient lamps.
• What are X-ray and gamma rays used for?

  Medical imaging and treatments.