Some questions in physics require long computational workings to derive to the answers. Hence, upon solving each problem, it is best to confirm that the answer you’ve obtained is the right answer and that your effort and time did not go to waste. In this article, we will go through the best ways to check your answers during your physics exam and confirm that you’ve gotten it right without committing any careless mistakes.
Develop the habit of working through physics problems using variables
One of the most straightforward strategies to check your answers is by implementing variables to solve the problems. This strategy has various benefits. One of the advantages is that the variables make it easier for you to refer back and check for calculation errors. In the case of any errors, they can be easily spotted and amended. If not for these variables, it would be time-consuming and challenging to check your workings, step by step. This is one of the strategies taught in many physics tuition centres. Another benefit is that it is easier to check the computed values when the numerical calculation is only done at the end of the problem. Hence, computational errors are only checked and verified at the end of the problem and not while working towards the solution. Performing numerical computations at the end also ensure that the common rounding errors are avoided as the numbers aren’t distributed throughout the solution. Learn to determine if your answers are reasonable
You can also check the accuracy of your answers by determining the order of their magnitude. This can be done by working with SI units and comparing it to units that you are familiar with. For example, when the question involves a baseball pitcher throwing a ball, a speed of 1 m/s is relatively slow, and 1000 m/s is unreasonably fast. It may be tough to notice this error if you are working with units that you are not familiar with. Therefore, the best approach is to use SI units and convert the units you are given to familiar units to help you relate your answers.
Don’t forget the units
For every computational result you find during your physics exam, ensure that you have written the units appropriately. Failing to write the units alongside your workings may lead to computational errors when you finally derive at your answer. The best strategy is to work only with SI units. This way, you can avoid the common mistake of computing the units wrongly. For instance, you should only work with values expressed in meters instead of kilometres, miles, and yards all simultaneously in the same working. The confusion of working with different units can cause even a straightforward question to seem complicated.
Build a physical intuition for checking your results
A common practice taught in JC physics tuition centres in Singapore is building an intuition for checking the accuracy of your results. Even though it is something that takes time to perfect, you would be able to check your final answer in terms of variables, and your solution should make sense if you can notice the increasing or decreasing variables according to the question. Also, read up on the standard range of limits for quantities and angles so that you can tell when you get outrageous values for your answer. This allows you to catch your mistakes early instead of only realising once you have wasted time deriving the wrong answers.
Solving problems in physics certainly requires a level of critical thinking. The methods mentioned above can help you spot your mistakes before submitting your paper during the exam.