Physics: How to Solve Numericals Without Panicking

Numericals scare many students, but almost every one can be solved by following the same steps. Practise this method until it becomes automatic.

The five-step method

1. Read the question twice and underline what is given and what is asked.
2. Write the given values with their units in a list. Convert units first if they do not match, such as centimetres to metres.
3. Write the formula you will use. If you are unsure, ask which quantities you have and which you need, then find the formula that links them.
4. Substitute the values carefully and calculate. Show each line of working.
5. Write the answer with its unit, and check that it makes sense.

Common mistakes

• Forgetting to change units, for example grams to kilograms.
• Mixing up similar formulas, such as speed and acceleration, or series and parallel resistance.
• Leaving out the unit in the final answer.
• Rounding too early. Keep the full number until the last step.

How to practise

• After learning a chapter, solve every solved example without looking at the solution, then compare.
• Keep one page of "all formulas of the chapter" with the meaning of each symbol. Revise it every few days.
• Practise a few numericals daily instead of many in one night.
• Draw a small diagram whenever a question is about forces, circuits or motion. A drawing often shows the answer.

Theory questions

Learn definitions word for word and learn the unit of each quantity. For reasoning questions, give a short answer in three parts: the law or idea, the reason, and the conclusion.

Our Physics teachers set weekly numerical practice and mark it with feedback. A free trial class will show you how it works.