Physics

• SI unit for time

  Seconds (s)
• SI unit for length

  Metres (m)
• Opisometer and trundle wheel


  • Can be used to measure the length of curved lines
• Vernier calliper and micrometer


  • Can be used to measure the width, thickness and length of small objects
• Area


  The amount of space taken up by a two dimensional shape
• SI unit for area

  Metres squared (m2)
• Mass


  The amount of matter in an object
• SI unit for mass

  Kilogram (kg)
• Volume


  The amount of space an object takes up
• SI unit of volume

  Cubic metre (m3)
• Graduated cylinder


  • Can be used to measure the volume of a liquid
• Random errors


  • Cause specific readings to be either too high or too low
• Energy


  The ability to do work or move something
• SI unit for energy


  Joule (J)
• Energy can be stored in certain objects and can also be transferred into other forms
• The law of conservation of energy states that energy cannot be created or destroyed, but can only be changed from one form to another
• Forms of energy

  • Chemical
  • Light
  • Sound
  • Heat
  • Gravitational potential
  • Strain potential
  • Electrical
  • Magnetic
  • Nuclear
• Energy transfers can be both useful and wasteful
• Energy transfer diagram


  • A way of representing the useful energy transfers that can take place in a device or process
• Sankey diagram


  • A way of representing the useful and wasteful energy transfers that can take place in a device or process
• Power


  The rate at which energy is transferred from one form to another
• Speed


  Distance (m) / Time (s)
• Acceleration


  Change in speed (m/s) / Time (s)
• If an acceleration takes place in the same direction as an object is moving, that object speeds up. If it takes place in the opposite direction, it slows down or decelerates
• Friction

  A force that opposes motion when two objects are placed in contact. It is a resistance to motion
• Drag forces

  Water and air resistance
• Density


  Mass (kg) / Volume (m3)
• Magnets

  • A piece of metal that attracts other materials
  • Have a north pole and a south pole
  • Like poles repel each other, unlike poles attract each other
• Magnetic field


  The space around a magnet that exerts a force on magnets and magnetic materials
• Electricity


  A form of energy that can be converted into other forms of energy and can move things
• Conductors


  Allow electric charges to move through them easily
• Insulators


  Do not allow electric charges to move through them easily
• Copper is a good conductor, so it is used for wiring. Plastic is an insulator, so it is used for covering wires
• Static electricity


  • Objects can be charged with it by friction
• Positive and negative charges

  • There are two types - positive charges and negative charges
  • An object that gains electrons is negatively charged, an object that loses electrons is positively charged
• Like charges repel, unlike charges attract
• Potential difference


  A measure of the energy available to move charges around an electric circuit and through components
• Series circuit


  • Components are connected in a single loop with each other and the battery
• In a series circuit, current is the same at all points and the voltages across all components sum to the source voltage
• In a parallel circuit, voltage is the same across all branches and the currents in each individual branch sum to the value of the series current in the overall circuit