Energy

• Principle of Energy

  Energy cannot be created or destroyed. Energy can only be converted from one form to another. Total energy in the isolated system remains constant.
• When the boy skates down the slope from W, he can only reach point Z.

  Suggest why he is unable to go beyond point Z.

  Some of the energy is converted to heat energy/sound energy, therefore there is insufficient Gravitational potential energy.

  
• Forms of energy:

  Gravitational potential, kinetic, elastic potential, chemical potential and more
• Sources of Energy

  Hydroelectric, wind, geothermal, biofuels, nuclear, fossil fuels, solar