Level 4 · Science S4.9

Energy, work and power

Energy can be calculated, and work and power tell us how much moves and how fast.

Planned. This book is not written yet. Below is its plan, which a teacher can already use.

You are ready for this book if

You can name four energy stores and describe one energy transfer.

The plan

  1. S4.9.1 Calculating energy stores
    • Calculate kinetic energy and gravitational potential energy
    • Use energy conservation to find the speed of a falling object
  2. S4.9.2 Springs and elastic energy
    • Use Hooke's law to calculate the extension of a spring
    • Calculate the energy stored in a stretched spring
  3. S4.9.3 Work done
    • Calculate work done as force times distance moved
    • Explain that work done equals energy transferred
  4. S4.9.4 Power
    • Calculate power in watts from energy and time
    • Measure your own power by timing yourself climbing stairs
  5. S4.9.5 Efficiency
    • Calculate efficiency as useful output over total input
    • Draw a Sankey diagram for a lamp or a motor
  6. S4.9.6 Specific heat capacity
    • Use specific heat capacity to calculate the energy for a temperature rise
    • Explain why coasts have milder weather than places far inland
  7. S4.9.7 Energy resources
    • Compare fossil, nuclear, solar, wind, hydro and biofuel resources
    • Judge which resources suit a sunny, windy or hilly place
  8. S4.9.8 Energy at home
    • Calculate the cost of running an appliance from its power and time
    • Compare the yearly cost of a filament lamp and an LED lamp

For parents and teachers

Level 4 fits learners who can already: follow a written argument. use letters for numbers. In many schools that is about 14 to 16, but start wherever the learner is.

Strand: Energy, light and sound. Written and drawn by attnom. Free to read, print and share.