## Overview This topic covers the basic properties of transverse and longitudinal waves and the differences between them. It introduces the wave equation and gives learners the basic ideas and skills they need to study both electromagnetic and sound waves. ## Working Scientifically Questions set on this unit will assess learners’ abilities to apply scientific knowledge to practical contexts; to present data in appropriate ways; to evaluate results and draw conclusions; to plot and interpret graphs. The specified practical work in this topic gives learners the opportunity to make and record observations; to keep appropriate records of experimental activities; to generate and measure waves using a microwave source. ## Mathematical Skills There are a number of opportunities for the development of mathematical skills in this unit. These include recognising and using expressions in decimal and standard form; finding arithmetic means; changing the subject of an equation, including non-linear equations. How Science Works There are opportunities within this topic for learners to carry out experimental and investigative activities, including appropriate risk management, in a range of contexts. ### Learners should be able to demonstrate and apply their knowledge and understanding of: (a) the idea that a progressive wave transfers energy without any transfer of matter (b) the difference between transverse and longitudinal waves (c) the term polarisation (d) the terms in phase and in antiphase (e) the terms displacement, amplitude, wavelength, frequency, period and velocity of a wave (f) graphs of displacement against time, and displacement against position for transverse waves only (g) the equation c = f (h) the idea that all points on wavefronts oscillate in phase, and that wave propagation directions (rays) are at right angles to wavefronts [[Specified Practical Work]] - Measurement of the intensity variations for polarisation