Energy transfers: work done, heat transfer

• What is the definition of work done?

  Energy transferred when a force moves an object
• What is the formula to calculate work done?

  $W =$$F \times d$
• What does $W$ represent in the work done formula?


  Work done measured in joules
• What does $F$ represent in the work done formula?


  Force applied measured in newtons
• What does $d$ represent in the work done formula?


  Distance over which the force is applied
• If a box is pushed with a force of 20 N over a distance of 5 m, what is the work done?

  $100 \, \text{J}$
• What are the three main methods of heat transfer?

  • Conduction
  • Convection
  • Radiation
• How does conduction transfer heat?

  Through solid particles vibrating and passing energy
• What is heat transfer?

  Movement of thermal energy due to temperature differences
• How does convection transfer heat?

  Through liquids or gases as warmer fluids rise
• How does radiation transfer heat?

  Through electromagnetic waves without physical contact
• How do work done and heat transfer differ in energy transfer mechanisms?

  Work done involves force; heat transfer involves temperature
• What are the key differences between work done and heat transfer?

  • Work done: energy transfer via force and movement
  • Heat transfer: thermal energy movement due to temperature differences
  • Work done formula: $W =$$F \times d$
  • Heat transfer has no specific formula
• How does work done result in energy transfer?

  By converting mechanical energy into kinetic or potential energy
• What happens when a force is applied to an object over a distance?

  Work is done, transferring energy to the object
• What is the formula for calculating energy transferred through work done?

  $W =$$F \times d$
• How does heat transfer result in energy transfer?

  By moving thermal energy from warmer to cooler objects
• What is thermal equilibrium?

  When two objects reach the same temperature
• What are the methods of heat transfer?

  Conduction, convection, and radiation
• How do work done and heat transfer relate to energy conservation?

  • Both transfer energy without creating or destroying it
  • Energy changes form or transfers between objects
  • Total energy in a closed system remains constant
• What happens to energy when work is done on an object?

  It converts to kinetic or potential energy
• How does friction affect energy conservation during work done?

  It converts some energy to thermal energy