Science

• 3 States of matter

  Solid, liquid and gas
• Solid -> Liquid = Melting - apply heat


  Liquid -> to Gas = Evaporation -apply heat

  Liquid -> Solid = Freezing - cool

  Gas -> Liquid = Condensation -cool
• Solid

  • not moving
  • low kinetic energy
  • low temperature
• Liquid

  • Moving more
  • More kinetic energy
  • More temperature(heat)
• Gas

  • Moving a lot
  • High kinetic energy
  • High temperature(heat)
• Heat- Type of Kinetic energy that particles(in things) possess

  -Measured in Joules(J)

  Temperature- The amount of heat energy an energy has

  -Measured in Celsius, F and K
• Potential energy

  • The energy that is stored
  • e.g Solar
  • Gravitational pot.
  • Chemical
  • Nuclear
  • Elastic pot.
• Kinetic energy

  • The energy that contains movement
  • E.g. sound
  • stored
  • Light energy
  • Electricity
  • Thermal(heat)
  • Wind
  • Mechanical
  • Elastic pot.
  • Magnetism
  • Wave energy
• Work- The ability to do something

  Energy- Required to do work
• Energy

  • can not be created or destroyed
  • can only be changed from one form to another
  • always conserved
• Energy can be transformed from one type to another

  For example,

  Electricity energy changed into heat and sound energy when bioling a jug(different energy type)
• Energy can be transferred from one object to another (Energy transfer)

  For example-

  Heat energy from the rocks cooking the food in a hangi. The type of energy doesn't change(same)
• Flow chart

  Chemical -> Mechanical -> Heat

  -> Kinetic

  -> Sound
• Toaster

  Electricity-> Heat -> Sound

  -> Chemical pot.

  Listening to music(ipod)

  Electricity -> Chemical pot. -> Heat -> Sound
• Barbecue -Flow chart-

  Chemical pot. -> Heat -> Heat -> Chemical

  -> Sound

  -Transformation- -Transfer- -Transformation-
• Energy transformations

  
  

  Light a match- Chemical pot. -> Sound -> Heat -> Light

  Burning Mg- Chemical pot. -> Heat -> Light
• ENERGY EFFICIENCY

  
  

  -Uses less energy compared to the energy required to make the device work

  
  

  Efficiency can be calculated using the following equation

  
  

  Efficiency(E)- Useful output energy

  Total output energy X 100
• Heat transfer- Conduction and Convection

  How does Heat transfer from object to object?


  -Heat always moves from a warmer place to a cooler place

  -When an object becomes hotter, it has gained heat energy(expands)

  -When an object becomes cooler, it has lost heat energy(compresses)
• Three types of Heat radiation

  
  

  1. Conduction
  2. Convection
  3. Radiation
• Energy efficiency

  
• How to work out energy efficiency!

  
• Energy efficiency

  
• Conduction

  • Heat is transferred from one particle of matter to another in an object without the movement of the object
  • "Touching"
• Convection

  • The movement that transfers heat within fluid and air(gas)
  • "Heat rises and cool sinks"
• Example of Convection

  
  

  The bottom of a pool is cold because it's cooling

  The top of the pool is warm because the heat rises to the top

  Hot air rises

  >Lighter

  >Less dense(particles spread out)

  Cool air sinks

  >More dense

  >Particles are close to each other
• Radiation

  -The transfer of energy by electromagnetic waves

  -Does not require matter to transfer thermal energy / no touching

  -currents/waves
• Types of Energy

  -Sound

  -Thermal(heat)

  -Chemical

  -Mechanical

  -Electrical

  -Light

  -Kinetic(moving)

  -Potential(stored)

  -Elastic pot.

  -Gravitational pot.

  -Wind

  -Wave

  -Magnetic
• Wave length = frequency = pitch of wave

  High frequency = short wave length = high pitch

  
  

  The louder you speak, the higher the wave is

  The deeper you speak, the wider it is

  High voice = shorter distance
• Heat transfer

  • Conduction
  • Convection
  • Radiation

  1. Conductor
  2. Insulator
• Sound formation

  • sound is produced by vibrating objects
  • the vibrating object causes the air surrounding it to vibrate
  • you make sound when your vocal cords vibrate
  • a sound wave is a series of compressions and rarefractions which moves away from the vibrating object.
  • sound waves are formed from moving particles, so if there are no particles there can not be any sound

  Pitch

  • Two major that determine what a noise sounds like: Pitch and loudness of the sound
• Conductor:

  • materials or substances which allow electric current to flow easily
  • allows the transmission of heat and light from one source to another
• Insulator:

  • a material that is a poor conductor(as of electricity or heat)
  • a material that doesn't easily allow heat and/or electricity to pass through it