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### AuthorTopic: How to do well in Physics from SAMAD (Phys 50, ATAR 99.95)  (Read 11811 times) Tweet Share

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##### How to do well in Physics from SAMAD (Phys 50, ATAR 99.95)
« on: December 30, 2011, 05:01:41 pm »
+28
Physics is a highly competitive subject and often it is criticised as being boring. Even those who did well in the subject find some aspects of the course dry (I did too, I must admit). Hence the key to success is firstly to “make” the subject interesting for yourself, and secondly to minimise errors in the exam so you can beat the competition. You need to get close to full marks in all graded assessments (SACs and both exams) to get a 50, and this is hard considering one small slip on the calculator or a dodgy/ incomplete explanation could cost you marks. I’ll cover specific exam tips first:

Unit 3:

Unit 3 covers two core areas of study: Motion and Electronics & photonics, as well as one detailed study (either of structures and materials, relativity or Electronics)

AOS 1: motion

The difficulty with motion is the conceptual errors and mistakes that you can make on the numerical questions, as well as the explanations that often arise.
Most of the questions in motion are numerical and often require only simple application of formulae. Even though they seem “easy” and they are compared to other questions, stay alert for making mistakes as you do them. The satellite motion questions are a prime example of this. They usually require simple “plugging into the calculator” procedures, but lagging calculators and miscued typing can lead to mistakes. The formulae are huge because they contain a lot of constants (pi, g, and the gravitational constant). I suggest you transpose these formula by taking all these constants out as a factor and converting the factor to a number with about 5 sig figs. This way you’ll have less to type and can check your answer. Remember to keep the original formula on your cheat sheet to show the examiner your full working.

Some motions questions have extra hidden tricks that require a greater depth of understanding to see. You should visualise each scenario in your head and make sure the formula you use takes the extra things into account. The most common examples of such questions are energy conservation questions and projectile motions. For the former, complications arise when bungee ropes or springs are included in a falling system, so you have to include all three of kinetic energy, grav. pot. Energy and elastic potential energy in your conservation of energy expression. Visualise the scenario to avoid making hidden assumptions. For the latter, it is best to avoid general case formulae and stick with your regular constant acceleration formulae. Double check with alternative formulae if you can.

To nail the explanations, include mathematical expressions of proportionality to show the examiner that you understand the connections between the maths and the theory. Explanations are often 3 marks (= 3 points), but it doesn’t hurt to put down 4 or 5 points to make sure you’ve covered what the examiners are looking for. You can almost wrote- learn specific points to slot into your explanations.

AOS 2: electronics and photonics.

The errors again arise here due to silly mistakes in the “easy” circuit analysis questions and errors in reasoning when looking at the effect of changing conditions to a voltage divider containing a photonic transducer.
To analyse circuits properly, stick to the hard and fast rules and apply these systems every time. e.g. voltage across a diode cannot exceed stopping voltage, voltages across parallel loads are equal, power dissipated in a circuit is the sum of power dissipated in each individual load.

For amplifiers, make sure you label every aspect of the voltage- time graphs (scale, units) every time. watch out for inverting/ non- inverting tricks and make sure you get the clipping right.

To reason with voltage dividers correctly, use a chain of steps. Ask, if I increase the light intensity, then…. And go from there step by step. Your explanations for voltage dividers should follow this same logical progression.
Make sure you know the properties of LD, LEDs etc. well, as some MCQs test these deeply.

Detailed study:

Since they are all MCQs worth 2 marks, it is all or nothing and this is where most people lose out in physics. To avoid silly mistakes, have all your formulae pre- transposed on your cheat sheet and apply fool- proof “systems” to solve each question.

Unit 4:

AOS 1: Electric power.

The mistakes arise from incorrect application of right hand rules, output graphs for AC generators and nitty gritty aspects of the explanations.
To apply the right hand rule correctly, don’t use your hand in the exam. Visualise a small person who can move around the diagram and position their right hand however they want. This allows you to find the convoluted direction correctly.

For AC generators, often people miss the effect of changing one variable on both the amplitude and period of the output. Its best to use the output formula E= NBAw*sin(wt). (see heinnamann physics) and knowledge of maths methods functions to draw the graphs.

For your explanations, know the differences between lenz’s and faraday’s laws correctly. Also know that both concern emf- lenz’s law has nothing to do directly with current. Aim for a logical progression and don’t write general things from your cheat sheet. Memorise explanations that allow you to slot in specifics of the question.

AOS 2: Interactions of light and matter.

The biggest challenge here is the abstractness of the concepts and the high proportion of written explanation questions.

The written questions are best tackled by determining the exact aspect that the examiners are looking for, especially with things like the photoelectric effect. State these first and then add the extra “just to make sure” points to make it easy for examiners. Remember to get your technicalities right with these as there are a lot of ambiguities. (e.g aperture: wavelength ratios for diffraction.) Always go by what VCAA says in their past assessment reports.

General exam tips: aim to do the numerical questions twice in the time given, using a different technique each time. you can either go straight through once or repeat them on the spot. I chose the latter because I found that I could pick my mistakes when my head was still “in” the scenario, rather than having to re- analyse it later on. The former technique gives you added reassurance of finishing however.

Preparation: in the early stages of each semester, I aimed to read the textbooks and achieve and understanding of the concepts rather than memorise them. You should critically read the text and question things you don’t understand. Seek answers to these questions to improve your understanding.

After finishing reading, take notes, focussing on the principles. Here it is a good time to begin formulating those wrote-learned responses to explanation questions- they’ll need constant tweaking as you learn more. Also note down derivations of formulae to improve understanding. Don’t go overboard with the notes though as practise q’s are key for phys.

I aimed to do as many practise questions as possible: I recommend the neap study guides and those in the heinneman textbook. Practise exams are also crucial. Sit them in exact exam conditions and learn from your mistakes rather than continually repeating past mistakes. Keep a logbook of past mistakes and hard questions- continually revise this in the lead up to the exam.

Finding interest: you’ve most likely picked physics if you have an interest in science. Try to put the content of the course in the context of your specific area of interest. (e.g I was interested in doing med, and had done work experience at a cardiology department. Many diagnostics and procedures of the heart used electricity (e.g Defibbrilation, ECG), so I found interest in electronics through that). For light and matter, marvel at the crazily complicated maths that Maxwell and the like invented to explain concepts- it can keep you absorbed.

Lastly, keep a positive mindset and good luck!!!

#### thushan

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##### Re: How to do well in Physics from SAMAD (Phys 50, ATAR 99.95)
« Reply #1 on: December 30, 2011, 09:28:49 pm »
+3
Nice work mate!

You need to get close to full marks in all graded assessments (SACs and both exams) to get a 50.

Not true, actually. I dropped a shitload of marks on the first paper. Got my Statement.

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• Victorian
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##### Re: How to do well in Physics from SAMAD (Phys 50, ATAR 99.95)
« Reply #2 on: December 30, 2011, 10:35:21 pm »
+1

#### b^3

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##### Re: How to do well in Physics from SAMAD (Phys 50, ATAR 99.95)
« Reply #3 on: December 30, 2011, 10:37:28 pm »
+2
I added it there not too long ago (maybe 20-30 mins). Sorry I forgot to tell everyone so.

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#### pi

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##### Re: How to do well in Physics from SAMAD (Phys 50, ATAR 99.95)
« Reply #4 on: December 30, 2011, 11:21:08 pm »
+22
Nice work mate!

You need to get close to full marks in all graded assessments (SACs and both exams) to get a 50.

Not true, actually. I dropped a shitload of marks on the first paper. Got my Statement.

#### thushan

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##### Re: How to do well in Physics from SAMAD (Phys 50, ATAR 99.95)
« Reply #5 on: December 30, 2011, 11:23:14 pm »
+1
It was enough for me to write off 48+ or so I thought :/
Medical Intern - Alfred Hospital (2018)
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#### enwiabe

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##### Re: How to do well in Physics from SAMAD (Phys 50, ATAR 99.95)
« Reply #6 on: December 30, 2011, 11:46:51 pm »
0
It was enough for me to write off 48+ or so I thought :/

You must have torched the 2nd paper. Full marks for sure

#### paulsterio

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##### Re: How to do well in Physics from SAMAD (Phys 50, ATAR 99.95)
« Reply #7 on: December 31, 2011, 12:07:05 am »
0
I lost 10.5 marks on exam 1 and managed to shell out a 46

#### MYDCT16

• Posts: 5
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##### Re: How to do well in Physics from SAMAD (Phys 50, ATAR 99.95)
« Reply #8 on: August 15, 2016, 10:58:21 am »
-2
Physics is a highly competitive subject and often it is criticised as being boring. Even those who did well in the subject find some aspects of the course dry (I did too, I must admit). Hence the key to success is firstly to “make” the subject interesting for yourself, and secondly to minimise errors in the exam so you can beat the competition. You need to get close to full marks in all graded assessments (SACs and both exams) to get a 50, and this is hard considering one small slip on the calculator or a dodgy/ incomplete explanation could cost you marks. I’ll cover specific exam tips first:

Unit 3:

Unit 3 covers two core areas of study: Motion and Electronics & photonics, as well as one detailed study (either of structures and materials, relativity or Electronics)

AOS 1: motion

The difficulty with motion is the conceptual errors and mistakes that you can make on the numerical questions, as well as the explanations that often arise.
Most of the questions in motion are numerical and often require only simple application of formulae. Even though they seem “easy” and they are compared to other questions, stay alert for making mistakes as you do them. The satellite motion questions are a prime example of this. They usually require simple “plugging into the calculator” procedures, but lagging calculators and miscued typing can lead to mistakes. The formulae are huge because they contain a lot of constants (pi, g, and the gravitational constant). I suggest you transpose these formula by taking all these constants out as a factor and converting the factor to a number with about 5 sig figs. This way you’ll have less to type and can check your answer. Remember to keep the original formula on your cheat sheet to show the examiner your full working.

Some motions questions have extra hidden tricks that require a greater depth of understanding to see. You should visualise each scenario in your head and make sure the formula you use takes the extra things into account. The most common examples of such questions are energy conservation questions and projectile motions. For the former, complications arise when bungee ropes or springs are included in a falling system, so you have to include all three of kinetic energy, grav. pot. Energy and elastic potential energy in your conservation of energy expression. Visualise the scenario to avoid making hidden assumptions. For the latter, it is best to avoid general case formulae and stick with your regular constant acceleration formulae. Double check with alternative formulae if you can.

To nail the explanations, include mathematical expressions of proportionality to show the examiner that you understand the connections between the maths and the theory. Explanations are often 3 marks (= 3 points), but it doesn’t hurt to put down 4 or 5 points to make sure you’ve covered what the examiners are looking for. You can almost wrote- learn specific points to slot into your explanations.

AOS 2: electronics and photonics.

The errors again arise here due to silly mistakes in the “easy” circuit analysis questions and errors in reasoning when looking at the effect of changing conditions to a voltage divider containing a photonic transducer.
To analyse circuits properly, stick to the hard and fast rules and apply these systems every time. e.g. voltage across a diode cannot exceed stopping voltage, voltages across parallel loads are equal, power dissipated in a circuit is the sum of power dissipated in each individual load.

For amplifiers, make sure you label every aspect of the voltage- time graphs (scale, units) every time. watch out for inverting/ non- inverting tricks and make sure you get the clipping right.

To reason with voltage dividers correctly, use a chain of steps. Ask, if I increase the light intensity, then…. And go from there step by step. Your explanations for voltage dividers should follow this same logical progression.
Make sure you know the properties of LD, LEDs etc. well, as some MCQs test these deeply.

Detailed study:

Since they are all MCQs worth 2 marks, it is all or nothing and this is where most people lose out in physics. To avoid silly mistakes, have all your formulae pre- transposed on your cheat sheet and apply fool- proof “systems” to solve each question.

Unit 4:

AOS 1: Electric power.

The mistakes arise from incorrect application of right hand rules, output graphs for AC generators and nitty gritty aspects of the explanations.
To apply the right hand rule correctly, don’t use your hand in the exam. Visualise a small person who can move around the diagram and position their right hand however they want. This allows you to find the convoluted direction correctly.

For AC generators, often people miss the effect of changing one variable on both the amplitude and period of the output. Its best to use the output formula E= NBAw*sin(wt). (see heinnamann physics) and knowledge of maths methods functions to draw the graphs.

For your explanations, know the differences between lenz’s and faraday’s laws correctly. Also know that both concern emf- lenz’s law has nothing to do directly with current. Aim for a logical progression and don’t write general things from your cheat sheet. Memorise explanations that allow you to slot in specifics of the question.

AOS 2: Interactions of light and matter.

The biggest challenge here is the abstractness of the concepts and the high proportion of written explanation questions.

The written questions are best tackled by determining the exact aspect that the examiners are looking for, especially with things like the photoelectric effect. State these first and then add the extra “just to make sure” points to make it easy for examiners. Remember to get your technicalities right with these as there are a lot of ambiguities. (e.g aperture: wavelength ratios for diffraction.) Always go by what VCAA says in their past assessment reports.

General exam tips: aim to do the numerical questions twice in the time given, using a different technique each time. you can either go straight through once or repeat them on the spot. I chose the latter because I found that I could pick my mistakes when my head was still “in” the scenario, rather than having to re- analyse it later on. The former technique gives you added reassurance of finishing however.

Preparation: in the early stages of each semester, I aimed to read the textbooks and achieve and understanding of the concepts rather than memorise them. You should critically read the text and question things you don’t understand. Seek answers to these questions to improve your understanding.

After finishing reading, take notes, focussing on the principles. Here it is a good time to begin formulating those wrote-learned responses to explanation questions- they’ll need constant tweaking as you learn more. Also note down derivations of formulae to improve understanding. Don’t go overboard with the notes though as practise q’s are key for phys.

I aimed to do as many practise questions as possible: I recommend the neap study guides and those in the heinneman textbook. Practise exams are also crucial. Sit them in exact exam conditions and learn from your mistakes rather than continually repeating past mistakes. Keep a logbook of past mistakes and hard questions- continually revise this in the lead up to the exam.

Finding interest: you’ve most likely picked physics if you have an interest in science. Try to put the content of the course in the context of your specific area of interest. (e.g I was interested in doing med, and had done work experience at a cardiology department. Many diagnostics and procedures of the heart used electricity (e.g Defibbrilation, ECG), so I found interest in electronics through that). For light and matter, marvel at the crazily complicated maths that Maxwell and the like invented to explain concepts- it can keep you absorbed.

Lastly, keep a positive mindset and good luck!!!