Newton's laws function less as a single claim than as a schema for analyzing motion. The second law supplies the form: causes enter as forces, and force equals mass times the second derivative of position. But the choice of second derivative is not neccesarily forced. Suppose we replaced it with holding the other laws fixed and keeping force as the same independently measurable quantity — what a spring balance reads. For each with , what experiment would expose that this schema is false?
Experiments to prove that the governing equation can not be taken as $F= m \frac{d^n x}{ dt^n}$ for $n$ except 2 in general
Brian

