Conservation of energy

• What is the topic of energy in Edexcel GCSE Physics?

  Energy
• How many energy topics are there in the GCSE?

  Two energy topics
• What is the measurement unit for energy?

  Joules
• What does the conservation of energy principle state?

  Energy cannot be created or destroyed
• What is the symbol for energy?

  J
• What does energy do?

  It allows work to be done
• What is gravitational potential energy abbreviated to?

  GPE
• What is kinetic energy associated with?

  Moving objects
• What is the abbreviation for kinetic energy?

  KE
• What is elastic potential energy related to?

  Stretched or compressed objects
• What type of energy do hot things store?

  Thermal energy
• What is chemical energy associated with?

  Reactions between chemicals
• What does nuclear energy involve?

  Energy in the nucleus of an atom
• What type of energy is associated with magnets?

  Magnetic energy
• How is energy transferred?

  Through light, sound, heat, and electricity
• What is the difference between heat and thermal energy?

  Heat is energy transfer; thermal is stored
• What does an energy transfer diagram represent?

  Energy transfers between stores
• What happens to gravitational potential energy when a ball is dropped?

  It converts to kinetic energy
• What is the equation for gravitational potential energy?

  ΔGPE = mgΔH
• What does 'm' represent in the GPE equation?

  Mass
• What does 'g' represent in the GPE equation?

  Gravitational field strength
• What is the value of gravitational field strength on Earth?

  10 m/s²
• What is the equation for kinetic energy?

  KE = 1/2 mv²
• What does 'v' represent in the kinetic energy equation?

  Velocity
• What is the relationship between GPE lost and KE gained?

  GPE lost equals KE gained
• How can you rearrange the kinetic energy equation for velocity?

  v = √(2KE/m)
• What is the formula for efficiency?

  Efficiency = useful energy in / total energy in
• What is the maximum efficiency percentage?

  100%
• What does dissipated energy refer to?

  Energy spread out to surroundings
• How can mechanical systems reduce energy losses?

  By lubricating to reduce friction
• What is used in electrical systems to reduce energy losses?

  Low resistance wires
• What is cavity wall insulation used for?

  To reduce heat loss in houses
• What is loft insulation designed to do?

  Stop heat escaping from the top
• What do draught excluders do?

  Prevent heat loss through gaps
• What is the purpose of curtains in energy efficiency?

  To reduce heat loss through windows
• What is the role of thermal conductivity in insulation?

  Lower thermal conductivity reduces heat loss
• How can the thickness of an insulating material affect heat loss?

  Increased thickness reduces heat loss
• What is the significance of a Sankey diagram?

  It shows energy transfers and losses
• What does the width of arrows in a Sankey diagram represent?

  The amount of energy transferred
• Why is energy efficiency always less than 100%?

  Energy is always dissipated as heat