Use your reading time wisely! <ul><li>You must not mark the paper, including highlighters in any way. </li></ul><ul><li>Use your scribble paper. </li></ul><ul><li>Identify the “gimme” questions. </li></ul><ul><li>Read the “extended response” questions and begin the planning process on your scribble paper. </li></ul>
<ul><li>Identify the “gimme” questions for you. Do them first! </li></ul><ul><li>This will </li></ul><ul><li>settle you down, reduce the nerves. </li></ul><ul><li>give your sub-conscious time to work on the harder questions. </li></ul><ul><li>allow you to be reminded of the ideas when you work on other questions. </li></ul>
Never spend time on a difficult question that you are not sure of, when there are questions that you can do. Plan your time. As a general rule, remember that you have 180 minutes to get 180 marks. If you want to have a few minutes to check over your work, you need to allow about 0.9 minute per mark. ie a question of 10 marks should take 9 minutes. Make learning these numbers part of your revision.
6. Marks may be deducted if you do not clearly show all steps in the solution of problems or if you do not define additional symbols. You should use diagrams where appropriate in your answers. 7. Use only black or blue pens for all work other than graphs and diagrams, for which you may use a sharp dark pencil. should
Unfortunately it was not clear that all students understood they had to complete both extended responses, and still maintain an essay format , that is write in paragraph format. As in the past examinations students and teachers need to understand that the extended responses are double marked and that the mark allocation for each, as written on the examination, should be halved if an indication of the number of relevant points that need to be made is to be obtained. This half score also includes communication marks, usually around 2 or 3 marks; hence even fewer points are required to obtain full marks, so time should be taken to ensure good communication and correct use of Physics terminology.
<ul><li>Answers given to the extended-response questions this year were poor, with Question 23 and 24 having the fourth and lowest average respectively on the paper. Students need to pay much more attention to answering these questions precisely, as many responses contained a lot of information that was not required, and lost marks for either not being concise or providing information that was wrong, with time being wasted. This could be in part due to the false assumption by students that each dot point is worth the same number of marks. On the other side of the spectrum, some responses were far too brief and showed a lack of complete understanding. Many responses did not contain ideas that were clearly expressed and lost communication marks. Grammar and spelling (even of words in the curriculum statement and question) were poor, and this coupled with illegible handwriting often detracted from the physics. Relevant diagrams and formulae are recommended, but they need to be explained, and not just stuck in as an optional extra. It is worth students using their reading time to plan these extended-response questions and then taking extra time and care in writing them during the examination. Students need to practise these under timed conditions and have them marked as is done in the examination to improve their performance. To do this teachers must remember they are double marked in the examination and that the mark allocation includes communication marks. </li></ul>
<ul><li>In the extended response question, plan your answer. </li></ul><ul><li>Before you commence writing a paragraph, know what you want it to say. </li></ul><ul><li>Make use of diagrams, but give them their own space. </li></ul><ul><li>Be succinct. </li></ul><ul><li>Write with clarity and accuracy. </li></ul><ul><li>Cram as much relevant Physics into your answer as possible. </li></ul>
Questions 21 and 22 are extended-response questions. Answer these questions in the separate script book. In answering these questions, you should: • communicate your knowledge clearly and concisely; • use physics terms correctly; • present information in an organised and logical sequence; • include only information that is related to the question. You may use clearly labelled diagrams that are related to your answer.
21. A car is moving with constant velocity along a flat horizontal road before a collision brings the car to rest. A built-in safety feature increases the time the car takes to come to rest. • Identify the forces acting on the car before the collision. Describe the relationship between the forces when the car is moving with constant velocity. • Explain, using the momentum form of Newton’s second law of motion, how the safety feature reduces the likelihood of injury to the driver. (16 marks)
23. An X-ray tube, as shown in the diagram below, is used to produce X-ray photons: Using the diagram above, state where electrons are produced and explain how they are accelerated in the X-ray tube. Explain the continuous range of frequencies and the maximum frequency in the spectrum of the X-rays. ( 16 marks)
<ul><li>24. Electrons can orbit the nucleus of an atom at various radii in discrete energy levels. There is an electrostatic force of attraction between the positive nucleus and the negative electron. The lowest two energy levels of hydrogen, n =1 and n = 2, have radii r 1 = 0.0529 nm and r 2 = 0.212 nm respectively, as shown in the diagram below: </li></ul><ul><li> </li></ul>[ This diagram is not drawn to scale. ] Using proportionality: discuss the factors that affect the magnitude of the electrostatic force of attraction; compare the magnitude of the electrostatic forces acting on the electron in the n = 1 and the n = 2 energy levels. ( 12 marks)
<ul><li>Once again the performance was poorer than expected in questions associated with the students’ understanding of the Assumed Knowledge and Skills found in the Appendix of the curriculum statement. Examples of this occurred with vector addition and subtraction; Newton’s laws of motion; momentum and its conservation in one dimension; energy and its conservation; partial reflection and partial transmission of light; regions of the electromagnetic spectrum; equation of a straight line; use of a tangent in right-angled triangles; direct and inverse proportionality; and the distinction between proportionality and linear dependence. These, along with the other Assumed Knowledge and Skills, obviously need to be revised briefly as the curriculum statement is taught. </li></ul>
<ul><li>Other simple suggestions that can be made to future students sitting the Physics examination based on the performances of students in 2006 are: </li></ul><ul><li>Try to do more than rote learn and endeavour to understand the physics: this will ultimately make it easier to do well. Know and understand the Experimental Skills section of the curriculum statement and how it applies to the scope. Perform and understand the key experiments related to the curriculum statement. If the school does not have the equipment there are usually simulations of them that can be found on the Internet. Set out answers in a logical order, working down the page. If there is insufficient room, then go to the extra space at the end of the booklet, making sure to label the answer with the correct question number. Define any abbreviations, acronyms or symbols that are used. Know how to use the calculator that is taken into the exam. After it is reset at the beginning of the examination, if it is a graphics calculator, reset the radians to degrees and put the display in scientific mode. Practise this in tests and practise examinations. Use pen for written parts of the paper, but do diagrams and graphs in pencil so they can be easily corrected. Take a transparent ruler into the examination so that lines of best fit and measurements can be made with them. A compass may also come in handy to draw circles. </li></ul>
I hope you all do a little bit better than you deserve. If you can put into practice what we have told you today, then you will deserve to do well. There is still time to make a huge difference – either way!!!