basics

• what type of waves are electromagnetic waves

  transverse
• what do electromagnetic waves transfer

  energy
• what type of spectrum do electromagnetic waves form

  a continuous spectrum
• list the order of the elctromagnetic spectrum in order of increasing wavelength

  gamma , xray , UV , visible light , infrared , microwaves , radiowaves
• what is the highest frequency electromagnetic wave

  gamma wave
• what is the highest energy electromagnetic wave

  gamma wave
• what properties are shared by all electromagnetic waves

  they are all transverse waves , they all travel at the same speed , they can travel through a vacuum
• what range of frequencies of electromagnetic waves can be detected by the human eye 


  400-700nm
• how do the speeds of em waves differ in vacuum and air 


  electromagnetic waves all travel at the same speed in vacuum and in air
• what can happen when radiation strikes an object

  it can be , reflected , absorbed , transmitted
• what do all objects emit and absorb

  infrared radiation
• what happens to the quantity of infrared radiation emitted by an object as temperature increases


  the hotter the object , the more infrared radiation will be emitted
• what happens to the type of radiation emitted by an object as temperature increases

  the hotter the body the shorter the wavelength of radiation released
• what is required for a body to be at a constant temperature

  the body would need to emit radiation at the same rate it absorbs it
• what can be said about intensity and wavelength

  intensity and wavelength distribution of any emission depends on temperature
• what is meant by intensity

  the power transferred per unit area , it is a measure of the energy transferred by a wave
• what will happen if the average power that an object radiates is less than it absorbs

  the temperature will increase
• what can be said about the rates of emission and absorption for a body increasing in temperature


  the body is absorbing radiation faster than it is emitting it
• give two factors that affect the temperature of the earth

  1. the earths rate of absorption and emission of radiatin
  2. the amount of reflection of radiation into space
• how does the earths atmosphere affect radiation

  the atmosphere largely absorbs or reflects radiation from the sun preventing it from reaching the earth , some radiation passes through which warms the earth
• what happens to the radiation emitted from earth

  it is absorbed and re emitted in all directions by greenhouse gases , resulting in the greenhouse effect which warms the earth
• what is the reason for an object increasing in temperature

  
  

  
  

  it absorbs more em radiation