Topics 4 and 9: Oscillations and Waves
Unit Notes
4.1 Oscillations
Nature of Science:
Models: Oscillations play a great part in our lives, from the tides to the motion of the swinging pendulum that once governed our perception of time. General principles govern this area of physics, from water waves in the deep ocean or the oscillations of a car suspension system. This introduction to the topic reminds us that not all oscillations are isochronous. However, the simple harmonic oscillator is of great importance to physicists because all periodic oscillations can be described through the mathematics of simple harmonic motion. (IBO Physics Guide 2016)
4.1 Oscillations
4.1.1

Describe examples of simple harmonic oscillations

4.1.2

Define the following terms: period, frequency, amplitude, displacement, phase difference

4.1.3

Define simple harmonic motion (SHM) and describes its identifying characteristics.

4.1.4

Explain the defining equation of SHM: a = (w)^2 * x

4.1.5

Describe the interchange between kinetic energy and potential energy during SHM

4.1.6

Sketch and describe graphs showing the relationships of acceleration vs. position, velocity vs. position (and velocity vs. time), displacement vs. time, and energy vs. time (and/or energy vs. position)

4.1.7

Solve problems graphically for acceleration, velocity, displacement and energy changes during SHM

4.1.8

Solve problems by calculation for acceleration, velocity (instantaneous and maximum), displacement, and energy changes during SHM

9.1 Simple Harmonic Motion
4.2 Traveling Waves
4.2.1

Distinguish between a wave pulse and a continuous progressive (traveling) wave. Describe how a traveling wave transfers energy

4.2.2

Define the terms wavelength, frequency, period and wave speed

4.2.3

Derive and apply the mathematical relationship between wave speed, wavelength, and frequency for a traveling wave

4.2.4

Distinguish between and give examples of both transverse and longitudinal waves

4.2.5

Explain the motion of particles of a medium when a wave passes through it for both transverse and longitudinal cases

4.2.6

State the constant speed at which all electromagnetic waves travel in free space. List the principal types of radiations in the electromagnetic spectrum and state their orders of magnitude for their wavelengths.

4.2.7

Explain the motion of particles in air as sound wave propagates, including the distinction between rarefactions and compressions

4.2.8

Describe at least one procedure that can be used to investigate the speed of sound experimentally.

4.3 Wave Characteristics
4.3.1

Describe waves in two dimensions, including the concepts of wavefronts and of rays

4.3.2

Sketch and interpret diagrams involving wavefronts and rays

4.3.3

define the terms amplitude and intensity

4.3.4

Solve problems involving amplitude, intensity, and the inverse square law

4.3.5

State the principle of superposition

4.3.6

Explain what is meant by constructive interference and by destructive interference

4.3.7

Sketch and interpret the superposition of pulses and waves

4.3.8

Describe what is meant by polarization of light

4.3.9

describe methods by which light will be come polarized

4.3.10

sketch and interpret diagrams illustrating polarized, reflected and transmitted beams

4.3.11

calculate the intensity of a transmitted beam of polarized light using Malus' Law

4.4 Wave behaviour
4.4.1

Describe the reflection and refraction of waves at a boundary between two media

4.4.2

Sketch and interpret incident, reflected and transmitted waves at boundaries between media

4.4.3

Solve problems involving reflection at a plane interface

4.4.4

State Snell's law, the definitions of critical angle and of total internal reflection

4.4.5

Apply Snell's Law in problems related to light passing from lower to higher optical density as well as from higher to lower optical density and total internal reflection.

4.4.6

Explain and discuss qualitatively the diffraction of waves at single slits and around obstacles

4.4.7

Describe a method for experimentally determining the refractive index of a transparent substance.

4.4.8

Solve problems involving Refraction of light (Snell's Law); apply the concept of the index of refraction to determining the speed of light in various media

4.4.9

Describe, qualitatively and quantitatively, the diffraction pattern formed through a single slit

4.4.10

Describe and sketch the interference patterns produced by diffraction at a single slit (light)

4.4.11

Explain and discuss qualitatively the diffraction of waves through double slits

4.4.12

Describe and sketch the interference patterns produced by diffraction at a double slit

4.4.13

State and apply the conditions for constructive and for destructive interference in terms of path difference

4.5 Standing Waves
4.5.1

Describe the nature of standing (stationary) waves

4.5.2

Explain the formation of standing waves in terms of superposition

4.5.3

Compare and contrast standing waves and travelling waves

4.5.4

Discuss the modes of vibration of strings and of air both in open and in closed pipes; Discuss the positions of the nodes and antinodes in the vibration of strings and of air in open and closed pipes

4.5.5

Define resonance, fundamental frequency, harmonics, displacement antinode and displacement node

4.5.6

Sketch and interpret standing wave patterns in strings and in pipes

4.5.7

Solve problems involving the frequency of a harmonic, length of the standing wave, and the speed of a wave. Include samples for vibrations on a string as well as both open and closed pipe resonance.
