Transverse and longitudinal waves

• What are longitudinal waves?

  Waves where vibrations are parallel to travel
• What is a characteristic of longitudinal waves?

  They have areas of compression and rarefaction
• What are compressions in longitudinal waves?

  Regions of high pressure due to close particles
• What are rarefactions in longitudinal waves?

  Regions of low pressure due to spread particles
• How can longitudinal waves be demonstrated?

  By pushing and pulling a stretched slinky
• How do particles move in a longitudinal wave?

  They move backwards and forwards between compressions
• What are transverse waves?

  Waves where vibrations are at right angles to travel
• What is the movement of particles in transverse waves?

  Particles move from side-to-side across wave travel
• How can transverse waves be demonstrated?

  By moving a rope rapidly up and down
• What are electromagnetic waves?

  Transverse waves with changes in electric and magnetic fields
• What do all electromagnetic waves do?

  Transfer energy as radiation from source to absorber
• Can electromagnetic waves travel through a vacuum?

  Yes, they can travel through a vacuum
• What is the speed of electromagnetic waves in a vacuum?

  300 million metres per second (m/s)
• What does the electromagnetic spectrum include?

  A continuous spectrum of electromagnetic waves
• What characterizes waves in the electromagnetic spectrum?

  Wavelength, frequency, and energy levels
• Which color has the lowest frequency of visible light?

  Red light
• Which color has the highest frequency of visible light?

  Violet light
• How does the frequency of electromagnetic waves affect their behavior?

  It determines their suitability for various uses
• What are radio waves used for?

  Communication such as television and radio
• Why are radio waves ideal for communications?

  They transmit easily and do not cause damage
• How are radio waves produced?

  By oscillations in electrical circuits
• What happens when radio waves are absorbed by a conductor?

  They create an alternating current
• What are microwaves used for?

  Cooking food and satellite communications
• How do microwaves heat food?

  By increasing the internal energy of food molecules
• What is infrared light used for?

  Electrical heaters and infrared cameras
• How does infrared light affect chemical bonds?

  It increases the internal energy of the bonds
• What is visible light?

  The light we can see
• What is ultraviolet light's effect on the human body?

  It can cause skin to tan or burn
• What are gamma rays produced by?

  Changes in the nucleus of an atom
• Why are X-rays and gamma rays ideal for internal imaging?

  They transmit through body tissues with little absorption
• What is ionising radiation?

  Radiation that can add or remove electrons from molecules
• What are the hazardous effects of ionising radiation?

  It can cause skin aging and gene mutation
• How is radiation dose measured?

  In Sieverts (Sv) or millisieverts (mSv)
• What is background radiation?

  Radiation that is always present around us
• What factors affect the level of background radiation?

  Jobs and places where people live