What's the formula of tensile force and elongation of physics grade one?
You're talking about Hooke's law. Hooke's law
Within the elastic limit, the elastic force of a spring is directly proportional to its deformation (elongation or compression value)
F = k · X "F", which means the elastic force "X" of the spring, is the length of spring extension or shortening
"K" is the stiffness coefficient of the spring. The international unit is n / m