Mathematical Calculations

In my slot with Help University, I wanted to cover some basic simple steps of Mathematical calculations but I didn't manage to in view of time constraints. So I will cover them here so that Physics students can systematically use these simple steps.

When reading a mathematical problem, shortlist information given which can be in the form of words or from the diagram. Then focus on the task or assignment or what you are supposed to calculate. Then select the appropriate formula from the list of formulae given in the 2nd page of the exam script. Subsequently substitute in the values and calculate the answer in the unit.

I shall begin with simple calculations and eventually proceed to more difficult ones. I have used different colours coding to show the different steps for example short list information is written in brown, the task is in green, the formula selected is purple with the 1st mark given beside it, the 2nd step of substitution in pink with the 2nd mark and the final mark is in blue for correct answer and unit. Sometimes the formula mark is omitted but the steps should be followed as the examiner can given marks for correct substitution and final answers with ecf ( error carried forward). This means the student can get some marks for the steps even if the final answer is wrong. In Physics, the focus is on the right steps and not just the right answer.

Our second example is as below.

Our 3rd example has slightly higher diffculty level.

The 4th example. I will no longer use the color coding but the steps are the same.

The 5th example

The 6th example

For the 6th example, Hooke's Law is used but this is the spring being compressed rather than being extended. The 7th example shows the calculation of resistance in parallel and is then added to show the total resistance. The voltmeter reading is proportional to the ratio of resistance which is 4 ohms in the total of 6 ohms. The last reading is the total voltage divided by the total resistance.

Do try to be calm when calculating - if you follow the steps, you will get some marks for the method. All the best for SPM!