Year 9 Science • AC9S9U04 • Authored homework
Energy Transfer: Wave & Particle Models
Use wave and particle models to describe energy transfer through sound, light, heat and electricity. Explain what each model shows well and where it has limits.
Part A
Short-answer questions
Define a wave in terms of energy transfer.
What is the difference between transverse and longitudinal waves?
Name the medium that sound travels through in air.
Explain why sound cannot travel through a vacuum.
Define wavelength and frequency.
What happens to particles in a solid when heat energy is transferred through conduction?
Explain why light can travel through space but sound cannot.
Give one example of energy transfer by radiation.
What is the role of electrons in an electric current?
Correct this misconception: “Waves move matter from one place to another.”
Part B
Long-answer questions
Compare how sound energy and light energy travel. Include the need for a medium, particle vibration and wave type.
Use a particle model to explain how heat is transferred along a metal spoon in hot water.
Draw or describe a wave model for water waves, labelling crest, trough, wavelength and amplitude.
Explain how increasing frequency changes the pitch of a sound and how increasing amplitude changes loudness.
Compare conduction, convection and radiation using examples from a heated room or kitchen.
A student says that light needs air to travel. Use evidence from space or sunlight to correct the idea.
Explain how an electric circuit transfers energy from a battery to a lamp using a particle/electron model.
Evaluate when a wave model is more useful than a particle model for explaining energy transfer.
Interpret a graph showing wave amplitude and wavelength, and explain what each feature tells you about the wave.
Write a full explanation of one everyday energy-transfer system, identifying the energy source, transfer pathway and model used.
Part C
Research and understanding task
Research one technology that uses waves or particles to transfer energy, such as ultrasound imaging, fibre optics, solar panels, wireless communication, headphones or thermal insulation. Explain the energy transfer model behind it and one limitation of the model.