Work Done and Energy Transfer

• What happens when a man pushes a box at constant velocity?

  A forward force is applied to the box
• What force acts against the man's push on the box?

  The force of friction
• What happens to the temperature of the box due to friction?

  The temperature of the box increases
• What type of energy is transferred from the man's muscles to the box?

  Chemical energy to thermal energy
• What do scientists call the energy transferred when a force moves an object?

  Work
• How is work calculated?

  Work done = force × distance
• What is the unit of work?

  Joule
• What does one Joule of work equal in terms of force and distance?

  One Newton moves an object by one meter
• What is another unit used for work besides Joules?

  Newton meter
• Why is only the vertical distance relevant when calculating work done against gravity?

  Because weight acts vertically downwards
• What is the relationship between work done and energy transfer?

  • Work is a measure of energy transfer
  • Energy is transferred when a force moves an object
  • Work is calculated using the formula: Work = Force × Distance
• What are the key points to remember about calculating work done?

  • Work done (in Joules) = Force (in Newtons) × Distance (in meters)
  • Distance must be in the line of action of the force
  • Work can also be expressed in Newton meters