AS物理的实验操作是获取准去数据的基础，课窝A/Olevel考试网小编今天针对AS物理实验paper3的第一个题型，给大伙讲讲如何通过数据的表述尽可能拿到好的分数。
paper3的第一道题目有固定的思路和统一标准的答题模式。
先根据题目的思路确定选择的测量仪，记录好第一组数据，这也就意味着告诉阅卷人你的仪器的精确度和误差，所以在写下一个数据的时候，记得保证精确度的一致。
第一组数据写完之后，改变自变量，分别得到六组因变量数据，然后做成表格和画图，求截距、求斜率、给定方程求常量。
以下，是CIE对AS物理Paper3的官方指导：
Paper 3 Tips: Practical Test
Do not panic if the context of the practical experiment appears unfamiliar. Where appropriate the question paper will tell you exactly what to do and how to do it.
If you find yourself in real difficulty setting up your practical equipment you may ask your supervisor for help, you will only lose one or more marks for this.
There are a number of things that you can do to save time: Draw a single table for your results in advance of taking any readings and enter your readings in the table as you take them (so that you do not waste time having to copy them up later).
This is also important because you must record all your raw readings before you calculate and record any average readings.
If the number of readings that you need to take is indicated in the question paper do not waste time by exceeding this number. Repeat your readings, but remember that it is only necessary to repeat them once (so that you have two sets of values) - do not waste time repeating them more than once.
All the raw readingsof a particular quantity should be recorded to the same number of decimal places which should in turn be consistent with the uncertainty in the readings.
The uncertainty in a measurement can sometimes be larger than the smallest interval that can be measured by the measuring equipment. For example, a stopwatch can measure time to a hundredth of a second, but human reaction times will mean that the uncertainty in the reading given by a stopwatch is (typically) 0.1s to 0.4s.
Each column heading in your table must contain both a quantity and its unit. For instance if you have measured time “t” in seconds, your column heading would be written as “t/s” (“t in s” or “t(s)” would also be acceptable). The quantity or unit or both may also be written in words rather than symbols.
The number of significant figures used in a derived quantity that you calculate from your raw readings should be equal in number to (or possibly one more than) the number of significant figures in the raw readings.
For example, if you measure potential difference and current to 2 and 3 sig figs respectively, then the corresponding value of resistance calculated from them should be given to 2 or 3 sig figs, but not 1 or 4. If both were measured to 3 significant figures, then the resistance could be given to 3 (or 4) sig figs.
When drawing your graph, do not forget to label each axis with the appropriate quantity and unit,using the same format for expressing column headings in a table. Choose a scale such that the plotted points occupy at least half the graph grid in both the x and y directions.
The x-axis scale should increase positively to the right and the y-axis scale should increase positively upwards. Use a convenient scale such as 1, 2 or 5 units to a 50px square as you will then be less likely to make a mistake with the position of your plotted points and it will be easier for you to read off points from your graph if you are calculating the gradient or finding an intercept. Similarly, it is good practice to mark values on at least every other 50px square.
All your plotted points should be on the grid; points in the white margin area will be ignored. Plot all your observations and ensure that they are accurate to half a small square. A fine cross (or an encircled dot) drawn with a sharp pencil is acceptable, but be careful not to obscure the position of your points by your line of best fit or other working.
When drawing your line of best fit, ensure you have an even balance of points about the line along its whole length. If it is a straight line, use a clear plastic rule so that you can see points on both sides of the line as it is being drawn.
Show all your working when calculating a gradient. It is helpful to draw the triangle used to calculate the gradient on the graph and to clearly label the coordinates of the vertices (accurate to half a small square). These values can then be used in the gradient calculation. The length of the hypotenuse of the triangle should be greater than half the length of the graph line.
If you are required to give a value for the y-intercept, it may be possible to directly read it off from your graph from an axis where x=0. If this is not possible you can instead calculate the y-intercept by using the equation of a straight line.
In this case you should substitute into this equation a pair of x and y values from your line of best fit along with your calculated value of gradient.
