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Ask a chatbot for "10 questions on projectile motion" and you often get ten questions at about the same level: some too easy to teach you anything, some so hard you give up and read the answer. A better request is a ladder: five questions on one concept, each a clear step harder, with a rule for when to climb.
How do you ask AI for questions from easy to hard?
Name the rungs yourself. If you only say "easy to hard", the AI may change the numbers but not the thinking. These five rungs work for most physics, chemistry and maths topics:
Recall: state the definition or formula.
Direct use: one step, numbers plugged in.
Two steps: combine it with one other idea.
Twist: the same idea in an unfamiliar form (reversed, a graph, a comparison).
Exam level: the concept plus reasoning, like a JEE Main or board long-answer question.
Copy this prompt and fill in the brackets:
"I am studying [concept] for [Class 11 boards / JEE Main]. Make a ladder of five questions on this concept only: rung 1 recall, rung 2 one-step use, rung 3 two steps, rung 4 a twist on the same idea, rung 5 exam level. Show one question at a time and do not give the answer until I reply. After my answer, tell me if it is right. If it is wrong, tell me which step went wrong and give me a different question at the same rung. Only move me up when I get a rung right."
The last two sentences turn a worksheet into practice that adjusts to you. If you get stuck halfway through a question, ask for a hint ladder instead of the full answer.
What does a good ladder look like?
Here is a ladder on the range of a projectile on level ground (g = 10 m/s²). Try each one before reading its answer.
Write the formula for range. Answer: R = u² sin 2θ / g.
A ball is thrown at 20 m/s at 30°. Find the range. Answer: 400 × 0.866 / 10, about 34.6 m.
At what angle is the range greatest, and what is it for 20 m/s? Answer: 45°, giving 40 m.
A launch at 60° gives the same 34.6 m as a launch at 30°. Which ball stays in the air longer? Answer: time of flight is 2u sin θ / g, so 2 s at 30° and about 3.46 s at 60°.
The range is four times the maximum height. Find the angle. Answer: R/H works out to 4 cot θ, so cot θ = 1 and θ = 45°.
AI-made questions sometimes contain errors; this guide on checking that an AI practice question can actually be solved shows how.
How do you know when to move up a rung?
Move up when you get a rung right, not when it just feels familiar. Aim for a high success rate, not a perfect one.
In "Principles of Instruction" (American Educator, Spring 2012), Barak Rosenshine describes a study of fourth-grade mathematics: in the classrooms of the most successful teachers, 82% of students' answers were correct, compared with 73% for the least successful. Rosenshine writes that the optimal success rate "appears to be about 80 percent": students are learning, and still challenged.
A 2019 Nature Communications paper, "The Eighty Five Percent Rule for optimal learning" by Robert Wilson and colleagues, found a similar sweet spot for a class of learning algorithms: training went fastest at an error rate of about 15.87%, or roughly 85% accuracy. That result is about models, not students, but it points the same way: practice you never get wrong is too easy.
Use these rules after each answer:
Right, without a hint, and you can say why: move up.
Right, but you guessed or took a long time: do one more question at the same rung.
Wrong: find the step that went wrong, then try a new question at the same rung.
Wrong twice at the same rung: drop down one rung and climb again.
If you are stuck on rung 1 or 2, you probably have a gap in the concept that more questions will not fix, so go back to the lesson. This post explains why practice works best just beyond what you can do alone.
Where can you get help when a rung keeps going wrong?
If the same rung keeps going wrong, study a full solution. The Fermi Problem Library has worked problems with a step-by-step solver that explains the reasoning rather than printing an answer. If you are not sure which concept to climb first, Fermi's AI tutor works out what you already know, builds a plan for the session and notices where you are stuck.
Parents can help without knowing the physics: ask which rung your child reached today and what went wrong on the next one.
Try one ladder tonight on this week's topic, and note the rung where you stopped.
