Travelling waves

Nature of science:

Patterns, trends and discrepancies: Scientists have discovered common features of wave motion through careful observations of the natural world, looking for patterns, trends and discrepancies and asking further questions based on these findings. (3.1)

• Travelling waves
• Wavelength, frequency, period and wave speed
• Transverse and longitudinal waves
• The nature of electromagnetic waves
• The nature of sound waves

Applications and skills:

• Explaining the motion of particles of a medium when a wave passes through it for both transverse and longitudinal cases
• Sketching and interpreting displacement–distance graphs and displacement– time graphs for transverse and longitudinal waves
• Solving problems involving wave speed, frequency and wavelength
• Investigating the speed of sound experimentally

Guidance:

• Students will be expected to derive c = fë
• Students should be aware of the order of magnitude of the wavelengths of radio, microwave, infra-red, visible, ultraviolet, X-ray and gamma rays

Data booklet reference:

• Electromagnetic waves are used extensively for national and international communication

Theory of knowledge:

• Scientists often transfer their perception of tangible and visible concepts to explain similar non-visible concepts, such as in wave theory. How do scientists explain concepts that have no tangible or visible quality?

Utilization:

• Communication using both sound (locally) and electromagnetic waves (near and far) involve wave theory
• Emission spectra are analysed by comparison to the electromagnetic wave spectrum (see Chemistry topic 2 and Physics sub-topic 12.1)
• Sight (see Biology sub-topic A.2)

Aims:

• Aim 2: there is a common body of knowledge and techniques involved in wave theory that is applicable across many areas of physics
• Aim 4: there are opportunities for the analysis of data to arrive at some of the models in this section from first principles
• Aim 6: experiments could include (but are not limited to): speed of waves in different media; detection of electromagnetic waves from various sources; use of echo methods (or similar) for determining wave speed, wavelength, distance, or medium elasticity and/or density