physics

• Magnetic materials


  • Iron
  • Cobalt
  • Nickel
  • Steel
• Magnetic materials


  Attracted to magnets
• Bar magnet


  • Has a north and south pole
• Like poles


  Repel
• Opposite poles


  Attract
• Magnetic field


  Area around a magnet where it affects magnetic materials
• Magnetic field lines


  Series of lines representing the magnetic field, pointing from N to S
• Detecting magnetic fields

  1. Plotting compass

  2. Iron filings method
• Drawings of magnetic fields

  • Attraction
  • Repulsion
• The Earth has a magnetic field
• Compass


  Can be used for navigation
• When there is a current in a wire there is a magnetic field
• Coil of wire carrying current


  • Increases the magnetic field strength
• Adding a magnetic core

  • Increases the strength of the magnetic field
• Increasing current or number of turns in a coil

  Increases the strength of a magnetic field of an electromagnet
• Uses of electromagnets

  • Cranes
  • Bells
  • Hard drives
• Sound


  Produced when an object vibrates, causing waves to travel through a medium
• Sound travels at different speeds in solids, liquids, and gases
• Sound travels much slower than light
• Wavelength and amplitude

  Characteristics of a sound wave
• Microphone and oscilloscope


  Can be used to detect sound waves
• Pitch/frequency and volume


  Characteristics of sound waves on an oscilloscope
• Measuring the speed of sound

  Speed = distance / time
• Audible range of sounds
• Energy


  Measured in Joules
• Thermal energy (heat)


  Transferred from hotter places to cooler places
• Temperature


  Measured with a thermometer
• Conduction


  Mechanism of heat transfer
• Convection


  Mechanism of heat transfer
• Radiation


  Mechanism of heat transfer
• Particles in a substance when heated

  Can undergo state changes
• Ways of insulating a home

  • Stop conduction
  • Stop convection
  • Stop radiation
• Light is a wave that travels in straight lines from a luminous source
• Light travels much faster than sound
• Luminous and non-luminous objects


  How we see them
• Opaque, transparent, translucent


  Characteristics of materials
• Shadows


  How they are formed
• Ray diagrams


  Rules for drawing them
• Angle of incidence and angle of reflection


  Relationship between them (law of reflection)
• Formation of an image in a mirror


  Described by ray diagram