Motion that occurs when net force along direction of motion is hooke"s law type of force. Force proportional to displacement and in opposite direction. Object is being either pushed or pulled toward equilibrium position (restoring force) Motion of a mass-spring system, pendulum bob, trapeze artist. First and last have maximum displacement, middle @ equilibrium. The spring force or restoring force; what brings the spring back to equilibrium. The spring force constant; it is a measure of the stiffness in the spring. Because it is always directed opposite to displacement. When x > 0 (to right), f < 0 (to left) When x = 0 (at equilibrium), f = 0. When x < 0 (to left), f > 0 (to right) Object initially pulled to x = a and released from rest. As object moves toward equilibrium position, f and a decrease, but v increases. At x = 0, f, a = 0, but v is a maximum.
