Learning Goal:To understand the use of Hooke's law for a spring. Hooke's law states that the restoring force F⃗ on a spring when it has been stretched or compressed is proportional to the displacement x⃗ of the spring from its equilibrium position. The equilibrium position is the position at which the spring is neither stretched nor compressed. Recall that F⃗ ∝x⃗ means that F⃗ is equal to a constant times x⃗ . For a spring, the proportionality constant is called the spring constant and denoted by k. The spring constant is a property of the spring and must be measured experimentally. The larger the value of k, the stiffer the spring. In equation form, Hooke's law can be writtenF⃗ =−kx⃗ .The minus sign indicates that the force is in the opposite direction to that of the spring's displacement from its equilibrium length and is "trying" to restore the spring to its equilibrium position. The magnitude of the force is given by F=kx, where x is the magnitude of the displa