There is a huge difference between remembering a formula and understanding a phenomenon. Most students who get a bad grade in physics know the formulas by heart. The problem is that they do not know when to use them. The Feynman technique, devised by the Nobel Prize winner Richard Feynman, is one of the most effective ways to close this gap.
In this article I show you how I apply it in lessons with my students, with concrete examples on three typical high-school topics: forces, the electric field and thermodynamics.
What the Feynman technique is, in short
The technique rests on a simple idea: if you cannot explain a concept to a ten-year-old, you have not really understood it. The procedure has four steps:
- Choose a topic and write it at the top of a sheet of paper.
- Explain it as if you were teaching someone who knows nothing about physics.
- When you get stuck, or use technical words to hide a gap, mark that point. That is your real gap in knowledge.
- Go back to the book, fill the gap, and try to explain again.
It sounds trivial but it is hard: the mind resists, because it is much easier to reread the book than to start speaking out loud.
Example 1: forces
Try to explain in words, without formulas, why a book resting on a table does not fall. Many students answer “because there is the normal force”. Fine, but what is the normal force? Where does it come from? Why is it exactly equal to the weight?
A good Feynman explanation goes like this: the book pushes the table downwards with its weight. The table, being rigid, deforms imperceptibly and reacts by pushing the book upwards with a force equal in magnitude and opposite in direction. The sum of these two forces is zero, so the book does not accelerate. If the table gave way, the normal force would be smaller than the weight and the book would accelerate downwards.
When you reach this level of explanation, problems like the inclined plane or the block resting against a wall become much simpler, because you are reasoning about interactions and not about symbols. I have written a dedicated article on typical physics mistakes in high school that links directly to this point.
Example 2: the electric field
The electric field is where many students lose the thread, because they go from Coulomb’s force () to the electric field () without understanding why the concept of a field is introduced.
Feynman explanation: imagine a source charge. You want to know “what it would do” to any other charge placed nearby. Instead of repeating the calculation for every different charge, you describe the region of space around the source with a single quantity, the field, which tells you how strongly and in which direction a test charge would be pushed. The field is therefore a property of space, not of the test charge.
When one of my students can say this sentence without stumbling, they get through 80% of the electric field exercises with no trouble.
Example 3: thermodynamics
Thermodynamics is the topic where the formula always beats the concept. The first law () gets memorised and applied mechanically, and when the problem changes one small detail the student freezes.
Try to explain it in your own words: the internal energy of a gas is the sum of the kinetic energies of its molecules. It can be changed in two ways, by heating it (you give it heat ) or by making it do work, or doing work on it, . If the gas expands it pushes the piston, so it does positive work, and that work comes out of its internal energy. Hence the minus sign.
This explanation lets you see at once why in an isothermal transformation : the internal energy does not change (the temperature is constant), so all the heat that went in is given back as work. Without Feynman, you risk remembering it only as “a formula to use when T is constant”.
How to fit it into your weekly study
The technique does not replace the book, it completes it. A good weekly routine is:
- Monday to Wednesday: read the chapter and work through guided exercises.
- Thursday: a Feynman attempt on two or three key concepts of the chapter, out loud or in writing.
- Friday: test exercises, choosing problems that require you to combine concepts.
After a few weeks you notice something: physics exercises stop being “finding the right formula” and become “translating the problem”. That is exactly where the difference between a 7 and a 9 is made.
The technique works best if you then check it with real problems: try a simulated physics test and list your mistakes in a column, using typical physics mistakes in high school to help you. If you are starting from a failed subject to make up, the revision plan is in catching up a failed physics subject. And if you use an AI assistant to check your explanations, first read how to use AI to study maths and physics.
When it makes sense to work with a tutor
The Feynman technique is powerful but has a limit: if you have a gap, you need someone to fill it reliably. When I teach physics in my physics lessons I always start with a Feynman attempt on a basic concept, because in ten minutes I understand exactly where to step in.
If you want to understand physics properly, and not just pass next week’s test, write to me on WhatsApp or through the contact form: I will suggest a path built on the gaps that emerge from the first two lessons.
