Alevel物理实验设计高分锦囊 记住这5步paper5拿满分

对于一些Alevel物理想要考A甚至是A*的同学来说，实验设计题是非常值得重视的，虽然实验设计在整个Alevel物理考试中只占据了15分的分值，但是因为实验设计相当于就是完全开放的叙述题，让很多学员无从下手。今天就给大家说说如何得到Alevel物理实验设计分值与实验步骤。

Alevel物理实验设计15分是通过以下5部分分布的：

1. Defining the problem, 3分; 

2. Methods of data collection, 5分; 

3. Method of analysis, 2分; 

4. Safety considerations, 1分; 

5. Additional detail, 4分. 因此我们只需要按分答题即可拿到这15分。

Defining the problem

在Definingthe problem中，这3分分别对应定义independent variable，dependent variable以及控制其他变量。Methods of data collection则跟具体题目有关，对于能得分的点是：label diagram，表明自变量如何测量，表明应变量如何测量，重复实验采用取平均值得方法来获取数值，以及如何才能得到实验需要的值。第三部分Method of analysis则相对简单，我们要表明所画的graph的横轴与纵轴所对应的值，和实验想要求的值的表达式（跟斜率与截距有关）。第四部分Safety considerations的1分也与具体实验内容有关，一般用“precaution linked to…”来回答。最后的Additional detail则更为开放，可对测量方法进行补充，也可以对安全问题进行补充，并且数据分析这块的补充肯定是“Relationship is valid if the graph is a straight line passing through the origin or having a y-intercept.我们来结合实际题目来应用下上述提到的方法。

A student is investigating simple harmonic motion using an electric vibrator. A plate is attached to the top of the electric vibrator. A small mass is placed on the metal plate as shown in Fig.1.1.

An alternating potential difference (p.d.) is applied to the vibrator. For a given peak p.d., there is a maximum frequency  at which the small mass remains in contact with the plate. The contact between the small mass and plate is lost when the frequency is greater than "f".

It is suggested that the relationship between and  isk=π² f² V

where "k"is a constant.

Design a laboratory experiment to test therelationship between "f " and "v" .

首先我们先完成Definingthe problem的3分：

1. "V" is the independent variable;

2.  "f" is the dependent variable;

3. keep the position of the mass constant.

其次完成Methodsof data collection的5个点：

1. labelled diagram showing signal generator connected to vibrator with two wires with mass on plate;

2. voltmeter connected in parallel with vibrator in a workable circuit;

3. measure "f" from signal generator;

4. detail regarding mass leaving the plate;

5. repeat each experiment for the same value of "V".

 Method of analysis的2分较为简单：

1. plot a graph of f² against 1/V;  

2. k = gradient * π²

关于Safety我们可以指出：precaution linked to mass leaving vibrating plate.

最后我们补充4点内容作为Additional detail：

1. 先写上万用句：relationship is valid if the graph is a straight line passing through the origin;

2. wait for vibrator to oscillate evenly;

3. method to determine period of oscillation from c.r.o;

4. clean surfaces of metal plate.

   
   

根据以上对于这道真题的分析，你学会运用这几步方法来做实验设计的题目了吗？可能同学们对这部分还是留有疑惑，但是只要同学们助力Defining the problem, 

Methods of data collection, Method of analysis,这3部分不失分，也会得到10分左右的分数，Paper 5一样能够拿到高分。如果同学们还有其他疑问的话，欢迎您前来橡沐咨询，橡沐的Alevel课程班欢迎您前来参加。

点击【Alevel物理考试重要原理 快来看看哪些是你不会的】、【ALEVEL物理A2难点分析 你的宇宙学有救了】查看更多。