3. Method of analysis(這里有3分,A1, A2 and A3) 3分所包含的內(nèi)容如下:
1、Question: Convert the equation that given in the question into y = kx + b form and state gradient and y-intercept, or convert the equation into y = kx form.
根據(jù)歷年的考題,一般考試中會(huì)出現(xiàn)三種形式的方程關(guān)系式。第一種就是上面說到的指數(shù)形式(考得比較多),第二種是不需要考生變形的,直接給你線性關(guān)系式,第三種是不給你方程,而是用英文描述兩個(gè)變量的關(guān)系(一般就是inversely proportional or proportional),需要考生自己寫出來。
2、State the details of the graphs to be drawn as appropriate. 這里占1分。需要考生寫出所作圖象的y軸與x軸分別是什么,這一分相當(dāng)容易拿,通過對(duì)題目中的方程變形,你就能確定y軸與x軸代表什么。拿上面的題目做例子,很明顯,lg h就是y軸上的值,lg f就是x軸上的值。答題格式如下:
4. Safety consideration. (1分,S1)
Candidates should be able to assess the risks of their experiment and describe precautions that should be taken to keep risks to a minimum.
These five marks will be available for additional relevant detail. How these marks are awarded will depend on the experiment that is to be planned, but they might, for example, include marks for describing how additional variables are to be kept constant, or for a diagram of a circuit needed to make a particular measurement or a description of initial experiments or an explanation of how to obtain calibration curves.
這一部分的分值最高,自由度也最高,但有幾個(gè)相對(duì)固定的得分點(diǎn)。
第一個(gè)得分點(diǎn)是描述通過數(shù)據(jù)畫出來的線的代表意義,由于畫出來的都是直線,所以第一個(gè)固定得分點(diǎn)是寫上Relationship is valid if the graph is a straight line (passing through the origin 如果是經(jīng)過原點(diǎn)的話)。