2D and 3D Wavefronts 11

11.1 Introduction

ESCEZ

You have learnt about the basic principles of reflection and refraction. Inthis chapter,

you will learn about phenomena that arise withwaves in two and threedimensions:

interference and diffraction.

See introductory video:VPpcu at http://www.everythingscience.co.za

11.2 Wavefronts ESCFA

Activity: Wavefronts

The diagram shows three identical waves being emitted by three point

sources. All points marked with the same letter are in phase. Join allpoints

with the same letter.

� � �

� � �

� � �

� � �

� � �

� � �

� � �

� � �

� � �

� AA � A�

BB B

CC C

DD D

EE E

FF F

GG G

HH H

What type of lines (straight, curved, etc) do you get? How does this compare

to the line that joins thesources?