topic 8 - energy forces doing work

• What happens to energy in a closed system?

  Total energy remains the same
• How does energy change in a motor?

  Electrical energy changes into kinetic energy
• What is work done in terms of energy transfer?

  Energy transferred by an external force
• Why is energy rarely 100% transferred?

  Some energy is dissipated as waste
• What causes energy dissipation in mechanical processes?

  Friction causing heat generation
• What is power in terms of energy transfer?

  Rate at which energy is transferred
• What is efficiency a measure of?

  Energy not lost as waste
• What does 'useful output energy' refer to?

  Energy that performs desired work
• What does 'total input energy' refer to?

  Total energy supplied to a system
• What is the relationship between power and time?

  Power increases as time decreases
• If a system has an efficiency of 80%, what does this mean?

  80% of energy is useful output
• What happens to energy in a system when work is done?

  Energy is transferred to the system
• How does electric energy transform into thermal energy?

  Work done against heating coils
• What is the significance of a closed system?

  No external forces affect energy
• How does friction affect mechanical processes?

  Causes energy dissipation as heat
• If a system's total input energy is 100 J and useful output energy is 80 J, what is its efficiency?

  80%
• What is the role of energy in a system?

  Facilitates work and changes in state
• How does energy transfer relate to system changes?

  Energy transfer causes changes in state
• What is the impact of energy dissipation on system performance?

  Reduces overall system efficiency
• What is the unit of energy?

  Joule (J)
• What is the relationship between kinetic energy and speed?

  Kinetic energy increases with speed squared
• How does the mass of an object affect its kinetic energy?

  Kinetic energy increases with mass
• What is the significance of the gravitational field strength in energy calculations?

  Determines the potential energy of an object
• What is the effect of height on gravitational potential energy?

  Higher height increases potential energy
• How does energy transfer occur in heating processes?

  Through work done against heating coils
• What is the relationship between work done and energy transfer?

  Work done results in energy transfer
• What is the role of external forces in energy transfer?

  External forces facilitate energy transfer
• How does the efficiency of a system relate to its energy losses?

  Lower efficiency indicates higher energy losses
• What is the impact of temperature rise on energy dissipation?

  Indicates energy loss to surroundings
• What is the significance of the unit watt?

  Measures power in energy transfer
• How does energy conservation relate to closed systems?

  Energy is conserved in closed systems
• What is the effect of friction on mechanical efficiency?

  Reduces mechanical efficiency
• What is the relationship between energy transfer and system stability?

  Energy transfer can affect system stability
• What is the role of chemical potential energy in batteries?

  Stored energy for electric transformation
• How does energy transfer relate to the efficiency of a system?

  Higher energy transfer improves efficiency
• How does the concept of energy conservation apply to real-world systems?

  Energy is transformed but not lost
• What is the significance of measuring energy in joules?

  Standard unit for energy measurement
• What is the relationship between energy and work done?

  Work done transfers energy to a system
• How does energy efficiency impact environmental sustainability?

  Higher efficiency reduces waste and pollution
• What is the effect of energy losses on system performance?

  Decreases overall system performance