- #1
greypilgrim
- 513
- 36
Hi.
In an ideal pendulum, energy is conserved. Potential energy gets transformed to kinetic energy and vice versa. However, momentum is not conserved.
The latter means that the pendulum is not an isolated system, which is plausible, since gravity is an external force. But why is energy conserved then? Under what conditions does an external force not change the energy in a system?
In an ideal pendulum, energy is conserved. Potential energy gets transformed to kinetic energy and vice versa. However, momentum is not conserved.
The latter means that the pendulum is not an isolated system, which is plausible, since gravity is an external force. But why is energy conserved then? Under what conditions does an external force not change the energy in a system?