| Why choose HSC Physics | | | | thinking about concepts in Physics, but it is a good |
| HSC Physics can be one of the most rewarding | | | | habit to always do this in order to verify and test |
| HSC subjects that is widely and commonly | | | | your own understanding. |
| available across schools in NSW. HSC Physics | | | | Good students would also have the ability to unify |
| tends to appeal to students with an interest for | | | | their understanding of various seemingly unrelated |
| quantitative subjects like mathematics. In fact, if | | | | topics. One thing unique about HSC physics as |
| one is to try to define physics, it would be applied | | | | opposed to other HSC sciences is that its topics |
| 2 unit maths. The mathematics in physics is | | | | are all latently linked, and based on a common set |
| certainly not difficult, but the problems in Physics | | | | of fundamental physical principles. What we mean |
| are structured in terms of real-world applications. | | | | by 'latent' is that these links are not immediately |
| Therefore students who have a keen interest in | | | | visible, and the ability to draw these links is what |
| the physical world and the theory behind its | | | | separates a student who gets 95+ in their HSC |
| behavior are advised to take physics. | | | | mark, versus a student who doesn't. For |
| In terms of scaling, HSC physics has always | | | | example, the same set of rules apply to forces |
| scaled quite decently. Traditionally and in recent | | | | on a cathode ray as those that are responsible |
| years, physics has had a scaled mean of about | | | | for the motor effect. And it is the same principle |
| 29/50, meaning it scales slightly under HSC | | | | (electromagnetic induction) which explains why |
| Chemistry, English Advanced and Economics. | | | | magnetars (if you do Astrophysics) have such |
| However physics has always scaled significantly | | | | intense magnetic fields. This is the same line of |
| better than biology, which is convenient since HSC | | | | thought that led Sir Isaac Newton to conclude |
| Physics and Chemistry has always had a synergy | | | | that it is the force of gravity which keeps the |
| about them. They are to a large extent similar | | | | Moon in a circular or bit around the Earth. |
| courses, both requiring a similar skillset from | | | | Different ways of thinking about one concept |
| students who want to do well. However, unlike | | | | For example, think of an induction motor: we are |
| HSC Chemistry, Physics is less experience-based, | | | | all taught by teachers that such a motor works |
| as there are less things upon which we need to | | | | because the squirrel cage 'chases' the spinning |
| refer to repeatedly throughout the course. ( For | | | | magnetic field, citing Lenz's law. However what if |
| example, in Chemistry, we had to know the | | | | you totally ignore your knowledge about Lenz's |
| common valencies, solubility rules, how to name | | | | law, can you try to explain how an induction |
| carbon compounds etc) | | | | motor works solely by using the right-hand push |
| Instead, Physics requires more of an ability to | | | | rule? Well actually you can, because as the |
| imagine things yourself and conduct what we call | | | | magnetic field sweeps past a part of the squirrel |
| 'thought experiments' in your own mind in order | | | | cage, that's like having a current move towards |
| to understand the concepts taught in the course. | | | | the opposite direction, which imparts a force along |
| This is more of a skill rather than a set of | | | | the cage onto the positive charge carriers as per |
| knowledge. For example, to gain a solid grasp of | | | | the direction of your palm. This dictates the |
| Einstein's theory of special relativity and the | | | | induced current flow, and if you then shift your |
| associated equations, it is all about your ability to | | | | thumb to point towards this current, you'll notice |
| get your head around how time dilation operates | | | | the palm now points towards the direction the |
| in different frames, and in relation to each other. | | | | magnetic field was moving towards. In effect, the |
| While theory helps and rote-learning the method | | | | cage actually does 'chase' the field, however as |
| of applying the equations, this approach is limited | | | | you can see, we can explain it in terms of first |
| in its usefulness since slightly tricky exam | | | | principles rather than rely on sweeping statements |
| questions can easily throw you off. | | | | like 'induction motors work because of Lenz's law'. |
| How to master HSC Physics | | | | Another practical example highlighting the same |
| To get better at HSC Physics, since many things | | | | point is attempting to explain the concept of an |
| are very abstract and conceptual (e.g. to | | | | event horizon in terms of escape velocity. |
| understand how an induction motor actually | | | | Without going into too much detail, recall that |
| works, or Einstein's equations of time and mass | | | | there is a formula to find escape velocity from a |
| dilation, or the cause of striation patterns in | | | | body of mass, and that it is inversely proportional |
| vacuum tubes), it is a good idea to ask a teacher | | | | to r, the distance from the centre of that mass. |
| or tutor as many questions as possible. That | | | | For black holes, since mass is all focused within a |
| means whenever there is some concept that you | | | | singularity of infinite density, there comes a point |
| don't understand, or even a tiny point within a | | | | where r is sufficiently small that escape velocity |
| wider concept, don't leave it alone. You should ask | | | | reaches, then exceeds c, the speed of light. At |
| all questions until you have a concrete | | | | the point where r makes the escape velocity |
| understanding of the concept in question before | | | | exactly equal to the speed of light, this defines |
| moving on. | | | | the boundary of the event horizon, beyond which |
| A good way is to constantly test your own | | | | no information can escape. If we further decrease |
| knowledge by connecting all the related concepts | | | | r (i.e. get closer to the black hole), by then the |
| together and seeing if there are any | | | | calculated escape velocity exceeds c, and from |
| contradictions that a revealed by connecting up | | | | Einstein's mass dilation equations, this could never |
| what you know. This is because physics is very | | | | physically be achieved. Therefore this is a more |
| conceptual in nature, and slightly different to the | | | | practical and unified way of thinking about the |
| other sciences (Chemistry and Biology). Physics | | | | concept of black holes and why they have an |
| revolves around understanding abstract concepts, | | | | event horizon. |
| most of which can not be experimentally tested | | | | As a student aiming for 95+ (HSC aligned mark) |
| within a school lab, and some concepts can never | | | | in HSC Physics, without a doubt, your depth of |
| be properly experimentally tested (e.g. whether | | | | knowledge, and the extent of drawing |
| the luminiferous aether really exists). | | | | connections between your conceptual |
| Successful physics students have a great ability | | | | understanding, will determine whether you will |
| to conduct thought experiments. What this | | | | reach your goal of 95+. That is, your ability to |
| involves is essentially testing out an idea in your | | | | unify your understanding of the various topics of |
| mind, following physical rules you have learnt, to | | | | physics will help you significantly when it comes to |
| see whether you arrive at a conclusion that is | | | | showing depth in your understanding in exam |
| absurd, or plausible. It's difficult to truly understand | | | | responses. |
| this technique and to what extent we use it when | | | | |