energy transfer by heating-P2

• What is the formula for power?

  Power = Work done / time
• How is power calculated using voltage and resistance?


  Power, P = \frac{V^2}{R}
• What is the formula for work done?

  Work = Force x distance
• What does specific heat capacity represent?


  It is the amount of energy required to raise the temperature of 1 kg of a substance by 1°C
• What is the formula for change in thermal energy?


  \Delta E = mc\Delta \theta
• What are the units for change in thermal energy?


  Joules (J)
• What is thermal conductivity?


  It is a material property that allows heat to easily transfer through its layers
• How does heat travel by conduction?


  Particles vibrate and transfer energy through the solid
• Why is dry air considered a good insulator?

  Because it has low thermal conductivity, reducing the rate of energy transfer by conduction
• What happens when insulation is lost?


  It leads to more leaks of energy
• What are some methods to improve insulation in buildings?

  • Use cavity walls with trapped air
  • Use thicker bricks with lower thermal conductivity
  • Install aluminum foil between walls
  • Use double glazed windows to prevent air escape
• What is the role of trapped air in insulation?


  Trapped air acts as an insulator
• How does aluminum foil contribute to insulation?


  It reflects heat and reduces energy loss
• What is the purpose of double glazed windows?


  To prevent air from escaping and improve insulation
• What is the relationship between thermal conductivity and energy transfer?


  Lower thermal conductivity reduces the rate of energy transfer