Use your knowledge and skills to help others succeed. The fact that the tension force (ftens) is greater than the perpendicular component of gravity (fgrav-perp) means there will be a net force which is perpendicular to the arc of the bob’s motion. There will be times at which the velocity is a negative value (for moving leftward) and other times at which it will be a positive value (for moving rightward). In addition to the potential energy (. When moving through the equilibrium position, the restoring force is momentarily absent. To the equilibrium position, there is no restoring force.

## Also see

Calculating the speed of a swinging pendulum bob. Therefore at any given place the period of the pendulum is dependent only on length of pendulum. In other words, the height must be measured as a vertical distance above some reference position. This force slows the bob down. So as the bob moves leftward from position d to e to f to g, the force and acceleration is directed rightward and the velocity decreases as it moves along the arc from d to g.

## Length of wire

By the time the bob reaches c, it has accelerated to its maximum speed. An analysis of the plots shows that the velocity is least when the displacement is greatest. When the bob of the pendulum is pulled aside and let go it swings back and forth under the influence of gravitational force of the earth.