When the pendulum bob reaches the mean position, the net force acting on it is zero. Why then does it swing past the mean position?
I have no idea.. i know that it has momentum ..but...
this is the inertial motion
Doesn't that mean it's at rest? I thought it had something to do with gravity pulling on the object? Because the bob is still moving so technically it's not at rest right?
http://www.citycollegiate.com/wave_soundXc.htm
To understand why the pendulum bob swings past the mean position when the net force acting on it is zero, let's first review the basic physics principles behind a simple pendulum.
A simple pendulum consists of a mass (the bob) attached to a rigid string or rod. When the bob is displaced from its equilibrium position (the mean position), it will experience a restoring force that brings it back towards the equilibrium. This restoring force is proportional to the displacement and acts opposite to the direction of the displacement.
When the pendulum bob reaches the mean position, the net force acting on it is indeed zero because the displacement is zero. However, other factors come into play that allow the bob to swing past this position:
1. Conservation of Energy: As the pendulum bob swings, it continuously exchanges potential energy (due to its height) for kinetic energy (due to its velocity). At the highest points of the swing (the turning points), all of the energy is potential energy, while at the lowest point (the bottom of the swing), all of the energy is kinetic energy. This energy conservation allows the bob to continue moving, even when momentarily at the mean position.
2. Inertia: The pendulum bob possesses inertia, which means it tends to resist changes in its motion. When the bob reaches the mean position, it still has momentum due to its previous motion. This momentum carries it past the equilibrium position, similar to how a moving object will continue to move even without any external force acting upon it.
In summary, although the net force acting on the pendulum bob is zero at the mean position, other factors such as conservation of energy and inertia enable it to swing past this point. These principles uphold the pendulum's oscillatory motion and allow it to continue swinging back and forth.