7. Waves

Start with Concept to understand a topic, then use Question Bank to check what you know.

5 topics · 16 learning objectives

Your progress

Sign in to see your mastery and mistakes.

  1. 7.1 Progressive waves

    1. • describe what is meant by wave motion as illustrated by vibration in ropes, springs and ripple tanks

    2. • understand and use the terms displacement, amplitude, phase difference, period, frequency, wavelength and speed

    3. • understand the use of the time-base and y-gain of a cathode-ray oscilloscope (CRO) to determine frequency and amplitude

    4. • derive, using the definitions of speed, frequency and wavelength, the wave equation v = f λ

    5. • recall and use v = f λ

    6. • understand that energy is transferred by a progressive wave

    7. • recall and use intensity = power/area and intensity ∝ (amplitude)2 for a progressive wave

  2. 7.2 Transverse and longitudinal waves

    1. 7.2.1Transverse and longitudinal waves

      • compare transverse and longitudinal waves

    2. 7.2.2Graphical representations of transverse and longitudinal waves

      • analyse and interpret graphical representations of transverse and longitudinal waves

  3. 7.3 Doppler effect for sound waves

    1. • understand that when a source of sound waves moves relative to a stationary observer, the observed frequency is different from the source frequency (understanding of the Doppler effect for a stationary source and a moving observer is not required)

    2. • use the expression fο = f sv / (v ± vs) for the observed frequency when a source of sound waves moves relative to a stationary observer

  4. 7.4 Electromagnetic spectrum

    1. • state that all electromagnetic waves are transverse waves that travel with the same speed c in free space

    2. • recall the approximate range of wavelengths in free space of the principal regions of the electromagnetic spectrum from radio waves to γ-rays

    3. • recall that wavelengths in the range 400–700 nm in free space are visible to the human eye

  5. 7.5 Polarisation

    1. • understand that polarisation is a phenomenon associated with transverse waves

    2. • recall and use Malus’s law (I = I0 cos2θ ) to calculate the intensity of a plane-polarised electromagnetic wave after transmission through a polarising filter or a series of polarising filters (calculation of the effect of a polarising filter on the intensity of an unpolarised wave is not required)