You Can Know the Formula and Still Not Know What Will Happen
Physics begins when an equation stops being something you calculate and becomes something you can use to predict reality A formula is not the end of a physical explanation. It is one of the ways we represent the relationship that makes the explanation possible. — Tymur Levitin A student sees: F = ma They know the formula. They can tell you: F means force. m means mass. a means acceleration. Give them two numbers and ask for the third. They calculate correctly. So we conclude: The student understands Newton's second law. Perhaps they do. But try something different. Do not give them numbers. Ask: If the same force acts on a much heavier object, what happens to its acceleration? Now they hesitate. Or ask: Two objects experience the same acceleration. One has twice the mass. Which requires the greater force? Another pause. Or simply: What does F = ma tell us about the physical world? Suddenly a formula the student seemed to know perfectly becomes much hard...