energy

• Food


  Provides energy that we need for activities
• All living things get energy from food
• Photosynthesis


  The process where plants make their own food using light, carbon dioxide and water
• Chlorophyll


  • Green substance found mostly in the leaves of plants
  • Traps light to enable plants to make food
• Photosynthesis


  1. Light is trapped by chlorophyll

  2. Carbon dioxide is taken in through stomata

  3. Water is absorbed by roots and transported to leaves

  4. Sugar is produced and transported to other parts of the plant

  5. Oxygen is given out through openings on leaves
• Factors that affect the rate of photosynthesis


  • Amount of light
  • Amount of carbon dioxide
  • Amount of water
• Animals


  Cannot make their own food, they obtain energy by eating other living things
• Living things on Earth depend on the Sun as the primary source of heat and light
• Energy in food can be traced back to the Sun


  Plants use sunlight to make food, the energy is then passed on to animals when they eat the plants
• Light energy


  Enables us to see
• Heat energy


  Makes things warm or hot
• Sound energy


  Energy that we can hear
• Electrical energy


  Usually generated from power stations and used to power machines and devices
• Kinetic energy


  Energy of motion
• Potential energy


  Stored energy
• Energy can be converted or transferred from one form to another
• Heat


  Things that are warm or hot
• Sound energy


  Energy that we can hear
• Electrical energy


  Energy usually generated in power stations, also stored in batteries and solar cells, can be changed to other forms like light, heat, sound
• Kinetic energy


  Energy of a moving object, depends on how quickly it moves
• Potential energy


  Energy stored in objects, includes chemical, gravitational, and elastic potential energy
• Chemical potential energy


  Stored in food, fuels, and batteries, can be changed to other forms like heat, electrical, light, sound
• Gravitational potential energy


  Energy stored in an object placed above the ground, decreases as height decreases
• For objects at the same height, the one with bigger mass has more gravitational potential energy
• Elastic potential energy


  Energy stored in stretched, wound-up, or compressed objects like rubber bands, toy springs
• Energy cannot be created or destroyed, but can be converted from one form to another
• Energy conversion


  1. Gravitational potential energy to kinetic energy

  2. Chemical potential energy to electrical energy to sound energy

  3. Electrical energy to heat and light energy

  4. Chemical potential energy to kinetic, heat, and sound energy
• energy converted to heat is most likely due to?

  friction