Detailed Instructions: In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.
Q: This law can be written in the Voigt notation as a six by six compliance matrix. One form of this law is the expression for the free energy of a deformed isotropic body, and includes the Lam coefficients. A generalization of it includes Young's modulus, and simple harmonic motion occurs when it is obeyed. This law includes a negative sign because the force exerted is always directed opposite to the displacement of the object. FTP name this law that governs springs and is stated as F equals negative k times x.
A:
Science