MATTER AND ENERGY

MATTER AND ENERGY

1. Transformations

   • Interactions
   • Physical agents
   • WORK
     • Work is done when a force acts on an object and causes its displacement. The force must act totally or partially in the direction of the movement.
     • Force
     • Displacement
     • ENERGY
     • Systems
       • Depending on if there is an exchange of matter and/or energy with the sorroundings, a system can be:
       • Isolated
         • Neither mater nor energy can be transferred to or from another system
       • Closed
         • Only the energy can be transferred but not matter.
       • Open
         • Matter and energy can be transferred to or from another system
   • Matter
     • - Change in position - Increase or decrease in temperature - Deformation or change in shape - Change in volume
   • Energy
     • Is the capacity of matter to transfer heat or to do work. As the matter transfer heat or does work, its energy decreases.
     • Forms of Energy
       • - Mechanical Energy - Chemical Energy - Thermal Energy - Internal Energy - Electromagnetic Energy - Nuclear Energy - Electrical Energy
     • Energy Conservation
       • Energy can be transformed from one form into another, or transferred from one body to another, but cannot be created or destroyed. So the total quantity of energy remains constant
       • Principle of Conservation of Mechanical Energy
         • Kinetic Energy
         • Potential Energy
     • Energy Degradation
       • All forms of energy can be completely transformed into heat, but heat cannot be completely transformed into other forms of energy
       • Heat

2. Usable Source of Energy

   • Non-renewable
     • From resources found in nature in limited quantities. - Fosil fuels - Nuclear Energy
   • Renewable
     • Comes from inexhaustible natural resources. - Hydroelectric -Geothermal -Solar -Wind -Tidal

3. Saving Energy

   • - Say no to crazy consumerism. - Turn off ligths and electrical appliances. - Buy low power consumption appliances. - Use energy saving bulbs. - Use natural light .... etc.

4. Momentum Conservation Principle

   • For a collision occurring between object 1 and object 2 in an isolated system, the total momentum of the two objects before the collision is equal to the total momentum of the two objects after the collision. That is, the momentum lost by object 1 is equal to the momentum gained by object 2. M1.V1=-M2.V2
   • Practice: Bouncing balls