IB Physics Higher Level (HL) Practice Exam

Waves are disturbances that travel through a medium, and their primary role is to transfer energy from one point to another without causing permanent displacement of the medium itself. When a wave propagates, it does so by oscillating the particles of the medium, causing them to move temporarily from their equilibrium positions. This oscillatory motion allows energy to be transferred across distances. While waves can carry information—such as in the case of sound waves or electromagnetic waves—this information transfer is a secondary effect of the energy transmission. It is the energy carried by the wave that allows information to be encoded and transmitted. Mass, on the other hand, is not transferred by waves; particles in the medium may oscillate, but the wave itself does not transport matter. Similarly, velocity refers to the speed at which the wave propagates, but it does not represent what is being transferred through the medium. Thus, when considering the fundamental property of waves, the correct understanding is that they primarily transfer energy through a medium.