Energy

• Energy causes a body to move
• Energy is the ability to do work
• Types of energy

  2 groups

  Stored energy:

  • Potential- due to the position
  • Nuclear- within the nucleus of an atom
  • Chemical- stored in chemical bonds of substances
• Energy in action:

  (Energy when..)

  • Kinetic- when a body is moving
  • Heat- allows atoms and particles to move
  • Light- used by plants to make food
  • Sound- energy that makes particles vibrate
  • Electrical- due to moving charges
  • Magnetic- allows magnets to move metals
• Law of Conservation of Energy

  Energy cannot be created nor destroy it is simply converted from one form into another

  Most of our energy comes from the Sun and it's converted into other forms and used or stored.
• None of these energy conversions are 100% efficient. Energy is often converted into 'non-useful' forms of energy= dissipation of energy
• Nuclear energy

  Nuclei(centres) of all atoms contain a huge amount of energy

  E=mc²=energy=mass x (speed of light)²= J=kg x (300,000,000)²
• Nuclear radiation also used in medicine to treat illness, to preserve food etc.
• Nuclear Fission: current method of extracting energy from atoms

  1. Large unstable atoms are split
  2. Radiation released is sued to heat water
  3. Steam produced turns turbines to generate electricity
  4. Disadvantage: waste products can damage health
• Nuclear fusion: method sun uses to produce it's energy

  1. Small atoms(H) are smashed into eachother to produce larger atoms(He)
  2. Radiation produced goes into space