Physics Unit 1 Revision

Physics Unit 1 Revision

1. Heating Houses

   • Energy in the form of heat, flows from a warmer body to a colder body. When energy flows away from a warm object, the temperature of that object decreases
   • A thermogram uses colour to show temperature; hottest areas are white/yellow, coldest are black/dark blue/ purple.
   • Temperature is a measurement of hotness on an arbitary scale. You dont need to use a thermometer and allows one objectto be compared to another.
   • When the temperature of a body increases, the average Kinetic energy of the particles increases.
   • Heat is a measurement of internal energy. It is measure on an absolute scale.
   • All substances have a property called Specific latent heat
     • The energy needed to raise 1kg of the substance by 1'C
     • Measured in joules per kilogram degree celsiuc ( J/kg 'C) and differs for different materials
     • the equation for energy transfer by specific heat capacity is: energy transferred = mass x specific heat capacity x temperature change
   • When an object is heated and its temperature rises, energy is transferred
   • Specific latent heat
     • The energy needed to melt or boil 1kg of the material
     • measured in joule per kilogram (J/kg) and differs for different materials and change of state
     • The equation for energy transfer by specific latent heat is: energy transferred = mass x specific latent heat
     • When a substance changes state, energy is needed to break the bonds that hold the molecules together. this explains why there is no change in temerature
   • When an object is heated and it changes state, energy is transferred, but the temperature remains constant

2. Keeping homes warm

3. A spectrum of waves

4. Light and lasers

5. Cooking and communicating using waves

6. Data transmission

7. Wireless signals

8. Stable earth