A spring pendulum (also called elastic pendulum or swinging spring) is a physical system where a piece of mass is connected to a spring so that the resulting motion contains elements of a simple pendulum as well as a spring. The system is much more complex than a simple pendulum, as the properties of the spring add an extra dimension of freedom to the system. For example, when the spring compresses, the shorter radius causes the spring to move faster due to the conservation of angular momentum. It is also possible that the spring has a range that is overtaken by the motion of the pendulum, making it practically neutral to the motion of the pendulum.
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- Pokorny, Pavel (2009). "Continuation of Periodic Solutions of Dissipative and Conservative Systems: Application to Elastic Pendulum". Mathematical Problems in Engineering. 2009: 1–15. doi:10.1155/2009/104547.