Matrix Blog

Physics

The Nature of Light | HSC Physics Study Guide Part 3

Read this article on the Nature of light if you want to make your HSC Marks shine!

Are you in the dark about HSC Physics? Don’t be! In this article, we illuminate the key concepts you need to know for The Nature of Light for HSC Physics to fulfil the NESA Course Outcomes.

The Nature of Light | HSC Physics Study Guide Part 3

The Year 12 Physics Nature of Light module is the first introduction to modern physics: quantum mechanics and special relativity. These concepts are challenging and non-intuitive and students very often struggle with them. Students must develop a clear understanding of these and learn how to apply them to obtain full marks in exam questions. In this third part of the HSC Physics study guide, we present key ideas from this topic in a distilled, logical way using flowcharts.

Matrix students are encouraged to organise complex ideas in ways that are easy to understand and visualise, and are taught how to use such techniques to answer longer exam questions.

 

1. The Wave Nature of Light

The earliest debate as to the nature of light that is studied in this topic is between Huygens’ wave model and Newton’s corpuscular (particle) model. While both matched the observed properties of light at the time, later experiments proved Huygens correct: light was a wave. This is outlined in the flowchart below:


2. What Type of Wave is Light?

Following the conclusion that light was a transverse wave, the question remained: what type of wave was it? The two scientist most responsible for the answer were James Maxwell and Heinrich Hertz, who concluded that light is an electromagnetic wave.

 

3. The Quantisation of Light

The concept of the quantisation of light and the photon model are the cumulative achievements of Max Planck and Albert Einstein. Planck suggested the notion of quantisation to better predict the emission spectra of black bodies, which was poorly explained by classical physics. Einstein expanded this idea to light, developing the photon model:

 

4. The Photoelectric Effect

The phenomenon that led Einstein to develop the photon model of light was the photoelectric effect, where light above a certain frequency caused electrons to be ejected from a metal. Einstein’s explanation is outlined below:

 

5. Special Relativity – Time Dilation and Length Contraction

One of the more confusing aspects of light is its relation to the nature of observations as outlined in Einstein’s Special Theory of Relativity. In this, Einstein adopts two postulates – that all inertial reference frames are equivalent, and that all observers measure the same speed of light regardless of their motion or the motion of the source – and uses them to make bold predictions about contradictory observations of space and time for observers in different reference frames. This is summarised below:

 

6. Special Relativity – Mass Energy Equivalence

One of the more famous outcomes of Special Relativity is the principle of mass-energy equivalence and the corresponding equation E = mc2. This arises from the relativistic momentum and mass dilation:

Looking for Part 4, From the Universe to the Atom?

Want to make your Physics marks shine brighter?

The Trial HSC Exams are around the corner! If you’re struggling with your Physics marks now, you’d better get on top of it before entropy really kicks in. Don’t worry, Matrix+ is here to help! Learn how to boost your HSC marks.

Written by Matrix Science Team

The Matrix Science Team are teachers and tutors with a passion for Science and a dedication to seeing Matrix Students achieving their academic goals.

 

© Matrix Education and www.matrix.edu.au, 2018. Unauthorised use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Matrix Education and www.matrix.edu.au with appropriate and specific direction to the original content.

Get free study tips and resources delivered to your inbox.

Join 75,893 students who already have a head start.

Our website uses cookies to provide you with a better browsing experience. If you continue to use this site, you consent to our use of cookies. Read our cookies statement.

OK, I understand