systems

• dynamic equlibrium is whne inputs and outputs are balanced
• postive feedback:

  • system experiments further change , disruption to equilibrium
• system models show us how components are linked through flows. they exist in a certain boundary , involve energy and/or matter flowing between components
• negative feedback:

  • stabilises system , allows it to maintain dynamic equilibruim
• 3 types of systems:

  • isolated system
  • closed system
  • open system
• isolated systems are rare , no inputs or outputs
• closed systems have inputs and outputs of energy but not matter e.g water or carbon cycle
• open systems have inputs and outputs of both energy and matter
• coastal systems are open systems
• exam q : outline the sources of energy at the coast (4 marks)

  • fetch - farther wave travels , more powerful it will be due to buildup of energy
  • longshore currents - strong movements of surface water that approach at an angle to shore , transport sediment , good source of energy