Energy Phys.

• What is a system in physics?

  An object or group of objects
• What happens to energy storage when a system changes?

  There are changes in how energy is stored
• What are common situations where energy storage changes occur?

  • An object projected upwards
  • A moving object hitting an obstacle
  • An object accelerated by a constant force
  • A vehicle slowing down
  • Bringing water to a boil in an electric kettle
• How can students calculate changes in energy when a system changes?

  By heating, work done by forces, or current flow
• What is the equation for kinetic energy?

  $E_k =$$0.5 \times m \times v^2$
• What does each variable in the kinetic energy equation represent?

  Ek is energy, m is mass, v is speed
• How is kinetic energy measured?

  In joules, J
• What is the equation for elastic potential energy?

  $E_e =$$0.5 \times k \times e^2$
• What does each variable in the elastic potential energy equation represent?

  Ee is energy, k is spring constant, e is extension
• How is elastic potential energy measured?

  In joules, J
• What is the equation for gravitational potential energy?

  $E_p =$$m \times g \times h$
• What does each variable in the gravitational potential energy equation represent?

  Ep is energy, m is mass, g is gravitational field strength, h is height
• How is gravitational potential energy measured?

  In joules, J
• What is the unit for mass in energy equations?

  Kilograms, kg
• What is the unit for gravitational field strength?

  Newtons per kilogram, N/kg
• What is the unit for height in energy calculations?

  Metres, m
• How do students show energy redistribution in a system?

  By using calculations on a common scale
• What is the significance of the gravitational field strength value in calculations?

  It will be given in any calculation